I think it’s super easy to spend to your income.
How old are your kids? If one is in nursery, I assume there’s only 2 of you needing mobile? I would imagine there are savings to be made there. My mobile cost is £7.50 per month — but this doesn’t include the handset.
I think you may be able to save on broadband too - I would expect to be able to make all calls on my mobile so would anticipate only really needing going broadband here. Even fibre broadband should be sitting at less than this. If you live rurally, you might find that John Lewis doesn’t put their prices up for you (many companies run more expensive options for rural folks).
If you got these down by £75 in total then that would be £900 per year, which has got to be worthwhile.
£700 pcm after petrol, mobiles, and eating out sounds like quite a lot. Is that also after council tax? I assume that holidays come after that, so that then leaves £450 pcm.
Obviously in months where there’s a car repair currently that will be tight. But most months, that sounds like a decent amount for days out, clothes and coffees?
I have my accounts set up so there’s a short term savings account (car repairs, MOT, yearly bills). This has the relevant costs divvyed up into 12 and I add to it monthly. In my case that’s £175pcm. For you it might be higher - I don’t put holidays into this but you could do.
I then have long term savings too. I don’t have a food account at the moment but it’s something I’m considering.