How to tell my sister?

[PosyBoo]

Apologies for the long post and please be kind as I’m just trying to do the right thing.
So a few weeks ago DN (14) was showing me a photo of a skirt I’d brought her and I saw something pop up saying “sexy body🔥 🔥”. She had a bit of a panic and snatched the phone away and then made some excuse about her best friend being saved as sexy on her phone. We were out for supper with her parents and my family so didn’t make a big deal of it but I could tell it was an Instagram message. DN is allowed Instagram and TikTok but not allowed to post photos of herself. Her parents are very strict about this.
Cut to this evening and I go on Instagram to have this account recommended for me. I recognised it was DN middle name so clicked on it and basically she has a full on Instagram account with a lot of photos of her and some videos linked to TikTok. Some of the photos are ok but pretty much all of TikTok videos are of her talking about boys, her being the one who “sucks every boys d”, saying her friends “need to get more d”, taking about secret boyfriends, who are in year 12 and just a load of other inappropriate stuff.
I honestly am so shocked. I know this probably sounds utterly ridiculous but I’m super close to DN, she’s always been a huge part of my life and regularly stays over. She comes on holiday with us every year and genuinely still acts so immature in so many ways.
She’s had a shocking year with being severely bullied and I’m just wondering if this is all a reaction to that. Trying to be “cool” and fit in? I don’t know, perhaps I’m just being incredibly naive but I just can’t believe this is the same girl who happily sits with my 7 year old and plays for hours on end.
So where do I go from here? Do I tell DN I know and that I’ll have to tell her parents but it’s only because I want to keep her safe? Or do I just go straight to my sister and tell her? I’m worried if DSis goes in all guns blazing that DN will just find a better way of hiding it and then she’ll be even more vulnerable.
I don’t want my DN to loose all trust in me but obviously my main concern is her safety. She looks so much older than her years and is incredibly beautiful. Some of the comments are just gross! Plus in some of the comments she says where she lives and in some of the videos she is wearing hoodies which say the school she goes to.
Any advice would be so hugely appreciated, I just need to know the best way to approach this for both my DN and my DSis, who I know will be absolutely heartbroken.

I’d want to know if this was my dd. I’d be horrified if DSis didn’t tell me something like this.
Very difficult position for you to be in, but DN’s parents need to know and need to be the ones to sort this.

I know you’re absolutely right. I think I’m just in shock so not thinking. I just feel so awful as DSis has honestly had the most awful year and this is just going to absolutely destroy her. But, like you say, I’d want to know if it was my DD.

Yes. I think you do need to tell her parents in order to keep her safe. Ideally, I'd want to tell dn first that that's what I was going to do, and explain why, but only if I could be sure that she wouldn't just go and delete everything or if I had screenshots, copies of any videos etc.

That’s actually such a good point, I didn’t even think about her deleting everything if I speak with her first. I think I have to tell my DSis and allow her to do what she thinks is best. I can’t sleep at all as I’m so worried about how much this will upset DSis and how much DN will hate me but I really have no other option. Hopefully one day DN will understand why I had to say something.

Thank you both for your advice. I just really needed someone to talk to.

This happened to me last year. I was horrified at what I found on my DDs (age 13/14) phone. Her online persona was so different to the way she was at home.

I took her phone away from her for a week or 2 while I totally buttoned down the security.

I now have all her pass codes and passwords, she isn't allowed to down load any apps that I don't approve of and I basically had a steep learning curve to become more savvy.

We talked at length about safety online and image and what her words, provocative images were conveying. She had made her accounts public (keeping them private was a condition of her being allowed social media) and as a consequence was being followed and messaged by many men.

Since then, I have checked her account very regularly, it has been a battle as she pushes the boundaries and I reserve the right to delete whatever I find inappropriate. We have a contract which means she will lose her phone if I find anything dodgy.

I initially banned Instagram but she set it up on a friends phone so I came to the conclusion that it was better for her to have it on hers so that I could monitor and advise.

Interestingly, I did notice that the 'edgy' side always seem to coincide with friendship issues and wanting to be accepted.

She is now almost 15 and has started to say, that she totally understands that it wasn't the best behaviour as she can now see younger girls she knows starting to experiment and she can see that it's not appropriate.

It will be a rocky road ahead and your dsis (and you) will have to learn to guide and advise until she is older. It helps to realise that this age of development means that teens can not reason anything logically and she will not see any risk in what she is doing.

Hold on and try to speak to your sister when she has a few hours to calm down and think of a plan before seeing her DD. She will be horrified and possibly see her daughter differently but it is all part of the process of allowing them to grow up. I have been utterly heart broken but after about a year, out relationship has developed and is now a more grown up one where guidance works much better.

Def speak to parents. It is probably related to wanting to fit in as opposed to anything that is really happening.
We had an issue when a relative saw DD’s TikTok, she’d put stuff on there that they knew nothing about (not sexual, but personal). They called us to see if we knew (we knew the info but not that it was on Tiktok). I spoke to dd who is essentially an adult and should know better re privacy on SM, and she made her account private (then later deleted all those vids and turned it back to public as I can see her account again - hasn’t used it for months tho).

Can you tell your DSis when DN is out somewhere? Because if you're worrying your DSis will "go in all guns blazing" then it might be a good idea for her to know when DN isn't close enough she can just talk to her that second. Obviously your DSis might start sending "Get home now! I know about TikTok!" texts and that would defeat the object of this and DN could delete it all. But from what you seem to be worrying about your DSis might need a couple of hours to think about this and how to help her DD without her just turning the house into a warzone because she's (understandably) reeling.

I’d speak to your niece first to be honest. She’s 14, 14 year olds have social media and that’s about the age to start pushing their boundaries with it. If her parents ARE super strict with socials, she’s probably pushing it more in reaction.
A chat with her about what’s allowed, consequences if she was found out and online safety is probably going to be the most effective option here.
If you tell your sister and she goes mad a) your niece will probably never confide in you again and that relationship could be seriously damaged and b) she’ll probably just get sneakier with her socials

Your DN doesn't need to know how her mother found out –it may be smart not to have this part mentioned so she still has someone in you for solace / advice.

Her mum might be angry, but at least that way she can kick back against her mum and STILL get the reinforcement of the safety message in a softer way from you.