Most 3 or 4 year olds don't understand money, they would rather have a 99p toy as long as they can open it. I feel putting a tenner in a card is more a pressie for mum.
I would give a present or a token to be spent in a particular shop, that then makes sure the money is spent on the child and not on the mother putting towards something else. £10 should be sufficient.
alittle pressy for a 4yrold.they like something to play with money means nothing to that age.my son is coming up 4 and i would be disapointed and he would if we opened cards and money dropped out.my lil girl is coming up 8 and even though she has alittle understanding of money she would still be disapointed .
I wouldnt give money to a 3-4 year old in a card? they have no concept of money, why not ask the mom what she likes, most little girls like peppa pig and the like, it doesnt have to be very expensive, up to £15 quid will buy something nice
If it's for your child to take to a birthday party and it isn't their best friend or a relative, i'd either spend or give a fiver. At that age they go to loads of parties and that seems to be the going rate, you'd end up bankrupt otherwise. You might even get a way with less. A small toy or some hair things from claires for a girl or a couple of matchbox cars or something for a boy and just stick in a packet of sweeties and they'll be happy as larry.
I give money to my daughter for grandchildren birthdays as they are awash with toys. Last time she bought some shoes for granddaughter with it, so obviously money is appreciated.