We have a joint income of 40k and are fine on this/ saving a little.
We buy lots of children's clothes from eBay and keep ours for years.
Buy what we can from Aldi, top up at Tesco and majority basics. Meat is a rare treat as we'll only eat happy meat.
Children activities limited - they'll have more in the winter eg, bouldering and then stop it in spring when they can climb trees instead!
Rarely buy food /ice creams out and about -
Take picnics and have cheap ice creams at home.
Buy fruit and veg seasonally.
Walk instead of drive if possible.
Lots of free days out - parks/ woods/ beach etc. cinema/ trampoline parks an occasional treat.
But we live in South Wales where life is cheaper than SE. We holiday abroad every other year only and book flights as early as poss and book air B and B. Use local supermarket for breakfast and some lunches, eat out once per day.
Just some ideas that may help.