You cant actually be fined for using parent spaces anyway, but surely you're just asking for trouble if parents with kids genuinely use the ones next to you.
Most parent and child spaces around by me would allow both cars next to each other to have the doors wide open and not even touch each other.
I used to think this was excessive and a waste of space until I was in the position of getting my son out of the car and into a waiting push chair. The space is most definitely needed.