Sorry you have lost your Mum / MIL - I'm sure that is affecting how you feel about things right now.
Agree that there is a kind of assumption that one goes back to work when the kids are at school, and if you are not going back to work, you should at least be writing a book, starting your own £1bn business from your kitchen or running the PTA, volunteering at the local hospital, making your own curtains, bread, clothes?.
Or we could just be.... and be happy for a while.
I've posted this before but I think we do have it all, the choice to put our family and our careers in whatever priority suits right now and the real possibility of changing the balance when our priorities change. There are always compromises, but if they are by choice, they are easier to deal with.
My mum is of the "stuck at home all those years" generation whereas for me it's a real choice to be here and a privilege.
Take your time, weigh up the options and make a choice, remember that nobody's life is really perfect, it's how we deal with the compromises that influences how happy we are with the outcomes. And, if it doesn't work, look at the whole thing again.