Nanny has offered free childcare

I think you should be careful how you handle this with your nanny, or there's a chance your kids could miss out in the future. At 8 there will be a lot of spontaneous playdates and meet ups arranged at the school gate. If your nanny can't ever discuss these without checking with you, then people will stop asking.

You either allow her to make offers as any normal parent would in conversation or you control everything - you won't be able to get the nice things you might have retrospectively agreed to without some things you wouldn't have agreed to, it will be all her judgement or nothing.

This is a big first ask, however, it wouldn't be unreasonable to ask how it came about and why she invited the other girl.

I totally agree.

I'm a nanny and would naturally ask the parents first but usually I've built up enough trust where it's a courtesy and I'd be surprised if they said no. Parents usually want their children to be able to spend time with friends and socialise - that's why they employ me rather than a nursery or wraparound provision.

Someone else said "why would she do it if she's not getting anything out of it?"
Because she's a good nanny who wants the children to have fun? Because it's easier with two 8yr olds who can look after each other and entertain each other?
Most of us do this as a vocation

Just say no. You pay her to look after your kids. You can arrange play dates, not her. It's very simple, but.you need to.nip it in the bud right now, not tomorrow.

It's extremely rude.

Is it on someone else's dime? How do you know that?

Why on earth have you not cancelled this immediately on hearing about it?

She's out of order, you need to put her back in her box.

This is so weird. Should your kids be lonely and friendless except when you're around??

Oh - come on. Arranging for another child to come for a couple of hours one afternoon in the holidays is one thing. Inviting another child for two days to include a high value ticketed day out on someone else’s dime is another thing entirely. And that’s without any discussion of whether it’s a sensible idea to take four young kids on your own to a theme park.

3 kids at such young ages is more than enough for one person to look after, especially when out and about; what if this child runs off/hurts themselves/has an allergic reaction to something you're unaware of - who is responsible then?

If it was a close friend of your DC and you knew the family etc then maybe, but an unknown?

I think you're well within your rights to say "that's not happening during work hours, you can many this other child in your own time."

This is so weird. Should your kids be lonely and friendless except when you're around??

@CantFindTheBeat I wish I worked for you.
I used to do after school pick ups and one of my employers used to agree to me having his friends kid also without even asking me or without extra pay. Didn't even cross his mind.
Other employers would check in with me first to check it was OK and pay me more if I agreed which is how it should be done.

I would never have done this as a nanny without speaking to the parent first. You have to tell her that it is something you are not comfortable with. Her first priority should be the family she works for, yours.

What does it say in your contract with her? Surely it's against her terms and conditions of employment. As well as against common sense.

How long has the nanny been with you, OP? She must be new, surely?

I had the reverse when my children were school-age - a couple of mums, in particular, asking our nanny if she could take XYZ to brownies as well, pick them up from clubs etc.

My nanny came to me about it and I say her response should always be: "I can't make any commitments, you'll need to speak to CantFindTheBeat directly".

They didn't.

I would not allow the nanny to do this, for all the reasons you have stated. They are all valid in my opinion.
If you give her notice for September be prepared that she may move on before this date. What sort of notice does she have to give to you?

That’s not ok. It’s your house not hers, she doesn’t have a right to invite anyone into your home.

I got suckered into a longer term arrangement many years ago. I was a very hard working numpty. My nanny organised to look after a younger child than my 2 year old three days a week. She got the extra cash.

I would speak to your nanny and ask for the parents' contact details. Say you are not happy about her dealing with 4 children on her own. I know parents do but that's on them and each child is theirs. You could also ask your 8 year old what she thinks but in the end it's up to you.

To look after

If she's self employed and you don't pay her tax then she can do this
Well, no. She can't; not whilst she's contracted to ok after op's children exclusively.

I honestly don't know what all the drama is -
You just inform the nanny - its not happening on her work time. You are her employer, you are paying her to look after your children. She has absolutely no authority to take anyone else's children in without your agreement.

I actually think your nanny has behaved inappropriately.

She has no right to take anyone else's children into your home/ day out or whatever, during her work hours.

Tell her she is free to look after whomever she wants outside her working hours.
End of story.

I found out because the nanny told me that she'd invited 8yo DC's friend to come with them on their days out next week. But she didn't check with me first and this isn't a close friend of DC, just someone in her class who has never been on a playdate with my DC before.

That’s out of order, in which case. If it was a close friend of your child’s, who you’d often had over, you could see her thinking that you wouldn’t mind and just not thinking through the financial/other implications. But this sounds very odd. Why would the nanny agree to it - potentially making her own life harder - if there’s nothing in it for her?

When I was a nanny many years ago, the neighbour would constantly drop off her daughter. It was a nightmare!! She'd also say "oh I okayed it with mum!" When she hadn't, or let her daughter walk across on her own as she got in the car and left for work. This kid was really badly behaved and didn't get on with the other kids that I was actually being paid to look after. Dreadful and a nightmare to manage for the nanny. I'd maybe make sure that the nanny hasn't been in some way "coerced" into it as I was.

She doesn't get to present you with this as a fait accompli
Tell her no! And remind her to run any decisions like this past you first, going forward.

Tell them that you have found out and are not happy as you were not asked in advance. Your DC is not best friends with this other child, you don't know their parents well and all day, for two days, is extreme for a first play date.

Then just tell her she needs to cancel it. You are paying her to look after your children, not other people's children. If you want play dates, you can organise them yourself. Just as you wouldn't (presumably) organise a play date and leave the nanny to look after them without her but-in. She works for you, you need to tell her what is acceptable.

She’s hoping the older two will occupy themselves. I wouldn’t be happy with that.