Hello of course you can it's what keeps us going . Do I take it that this little apple tree is in a pot? If so I would use John Innes No 3 loam based potting compost - you should be able to get it from any good garden centre. This has the nutrients the tree will need for growing longterm in a pot.
If you're an 80smaniac I imagine that your daughter is not very old and this little tree is very important. I will warn you that apple trees grown from seeds are usually not very fruitful - however, just occasionally one will turn out to be amazing (e.g. Coxes Orange Pippin and Bramley Seedling). But whether or not this tree goes down in posterity for its amazing apples, it is important to you and your daughter that it grows well. Will you have the room in your garden to plant it into the ground when it gets bigger, or do you want to keep it in a pot in case you move house, then you can take it with you?
I've not grown fruit trees long term in pots, so hopefully someone else will step in here and give some more advice.
It's lovely to encourage youngsters - is your daughter growing any other plants?