Kids age gap and struggling

[WeatherOrNothing]

I have two DC, 9yo boy and 3yo girl.
DS is on the quieter, easy going and introverted side. DD is the opposite.
She is feisty, loud and very dominating. Ds adores her and will do anything she wants, however she’s learnt this and can be quite mean to him. She is very strong willed.
The age gap means she is still quite little and demands a lot of my time and attention, which means Ds is often pushed aside.
if i try do something with DS she takes over , she does the same with DH.
im just exhausted trying to manage them. Ds becomes very sad often when she is just mean to him for no reason. Time out doesn’t work, she’s also incredibly stubborn.
how do people manage their daily lives with kids with a big age gap?

You need to step in and protect your DS here. It's really common for the 'easy' older child to get pushed aside when a demanding toddler comes along, but you are currently letting a 3-year-old dictate your family dynamic and it's making your 9-year-old miserable.

She takes over because you and your DH are letting her. If you are playing a game with your DS or having 1-on-1 time, and she tries to barge in, your DH needs to physically remove her from the room. She will scream, she will have a massive tantrum, and she will be incredibly stubborn about it, but you have to ride it out. Right now, she knows that if she pushes hard enough, she gets her way and her brother gets pushed out.

You also need to make sure your DS has a totally safe space away from her. His bedroom needs to be a strict DD-free zone. If she is being mean to him, immediately intervene. Say firmly, "We don't treat your brother like that," and remove her from the activity. Don't rely on him to stand up to her, because he's a gentle soul and he just wants to please her. It is your job as the adults to manage her behaviour and protect his peace.

It is utterly exhausting dealing with a threenager, I know, but you have to break this habit now before the resentment really sets in for your DS. Divide and conquer with your DH. Take DS out of the house for just the two of you, even if it's just a quick trip to a cafe or the park, while DH deals with the toddler. He needs to know he is still a priority, even if he doesn't shout the loudest.

I’d be much stricter with the three year old. What do you mean time outs don’t work? You’re the parent! Your poor DS….

My sister had this with the genders reversed. In the end they had to take a stand as their elder daughter was starting to lash out. It was a tough few months with relentless screaming from the preschooler but it was worth it and now he’s a feisty but pleasant seven year old.

I completely agree with you both. Dh, ds and I seem to be the same personality type very calm and easy going so dealing with another personality type is challenging us in many ways.
We do take her away and also encourage ds to speak up and say he won’t play with her if she is being mean, but he also seems to defend her. The other day she smacked him and I really told her off - he jumped in to say ‘oh mum she’s 3 it wasn’t a hard smack so don’t scold her’ . She can do no wrong in his eyes and that’s part of the problem too.
Dh is firmer than me but again backs down when dd says the right words.
I feel quite out of my depth here. Very anxious when we’re out and about too as she’s quite vocal and will say literally what’s on her mind.