We are planning on explaining that our donor wanted to give us the very special gift of a child since we couldn't do it on our own. The explanation will take different forms as Toby gets older and can understand on new levels. I don't think there is anything wrong with how you want to go about it - there is nothing different about your situation and your friend's adoption situation - either way, the child has two loving parents who just happened to need a little bit of assistance creating their family. I think things will flow naturally, don't let your friend scare you into thinking it has to be a big deal.