A teacher at school is pregnant, both have asked how the baby got there, very interested to see the bump has got bigger.
Fine with dd age 4, we have the Usborne Flip Flap Body Book which explains about eggs and sperms and the baby is pushed out.
I have the Usborne pocket scientist book for my 7 year old ds, it goes into more detail and explains briefly about sex (not read it to him yet) - I just told him that parents 'make the baby' and he said "do they make the heart?" then I explained about eggs and sperms, and he seemed satisfied (for now) when I said they just make babies with their bodies, without going into details.
How have others answered the question for 7 year olds?