Help me to handle this.

[BarnabybearinDenmark]

Hoping lovely mumsnetters can help with this situation that crops up fairly regularly.
I'm a single mum to a three year old girl. When I go out I hire a babysitter. I rarely drink, not teetotal, just not that fussed and plus looking after a three year old with a hangover is hell!!
I have a group of friends that I see regularly, we go out but I usually drive and don't drink.
Firstly I get put under huge pressure to leave my car behind and "let my hair down" I feel like I have to give a valid reason why I'm not drinking..... I have a babysitter to pay and I hate being hung over and I don't really enjoy it, don't seem to cut it.
Secondly, when I do drive they all then say "well you can be our taxi then"
Which I'm actually fine with (even though it would take an extra hour to drop them all off) except that then I'm put under pressure to stay "just another hour, just another half hour etc" and made to feel like a kill joy because I'm ready to go home.
A typical night out starts at about 4pm so I'd like to go by 11pm really.
Help me to stop me being a pushover so I can enjoy my evening
Thank you!

Either be firm and put your foot down or you just tell them you’re going to join them at the venue and you’re leaving at x time to get back for the babysitter.

If you want to leave at 10, tell them in advance that you want to leave at 9.30. When it gets close to 9.30 and you start talking about leaving, you can then be "persuaded" to stay an extra half an hour. Do be firm about leaving when you actually want to.

If they want to leave later, they can get a cab

Thank you, @chocolateworshipper 's suggestion may just work, they will get a taxi if I leave before they're ready but it almost always becomes quite unpleasant first and on a few occasions I've felt almost pushed out of the group afterwards. They all have husbands at home so have a bit more flexibility.

Say you're getting a taxi in, then drive in as you need an early night. Don't get drawn into conversation about it. Apologise that you can't stay late as your babysitter has a cat that needs antibiotics or something insufferable dull and duck in and duck out at times to suit yourself.

And have fun.

4pm-11pm? And you are the only one not drinking?

Fuck would I be playing chauffer to everyone who has been on the lash for 7 hours.

And you pay a babysitter for this???

They don't sound very nice, your friends. If they don't care about how your feel what even makes them friends at all?

Maybe find some nicer friends?

@Crunchymum I do enjoy it mostly to be fair, it's the sitting drinking part I find tedious but we'll do other things earlier like cinema, theatre, meals, break out rooms etc. Which is why we meet so early but yes by 11pm they are all pretty drunk and can get a bit forceful because they're drunk. Then, because they were all on the same "side" as it were, with only me on my side. They feel that I was to blame for the falling out even though all I really did was try to go home. Fww I'm happy to go home and leave them to get a cab, I'm not trying to persuade them to come with me.

Could you leave before the drinking starts? When they're more reasonable. Do the activity earlier in the day and dinner and then head home.

They drink all through but yes I've messaged them to say that I'll be leaving after the show tonight.
@FurrySlipperBoots and @NuffSaidSam you might have a point they are all very strong characters whereas I'm (I suppose) a bit of a wimp by comparison. They're not bad people at all but I do tend to get a bit steamrollered by them.