Hi Nichola
Ideas off the top of my head:
Making Salt dough shapes- we make them one day and then colour them in another day. I found the colouring in is batter with felts than paint and the wet paint melts them!
Building an assault course inside. - walk along a dressing gown tie thingy, jump over a cushion, balance a bean bag on your head etc
Indoor wet play , if you ve got towels or a waterproof sheet to put down.... We do a washing up bowl with water and bubbles and give them things to clean , toys, cups etc and an old tooth brush.
Find the cuddly toys or what ever else they want to hide. My two will play this for hours!
Paint stones
Threading beads/ buttons onto pipe cleaners.
Guess what animal I m being
That's all I can think of at the mo, will come back if I think of any more