I don’t really understand that analogy. A man can’t have a baby, not because another human has told him he can’t, but because he’s not physiologically able. Both a man and a woman are physiologically capable of entering a priesthood. The only difference is, the woman is told she can’t. There is no other impediment but her gender, defined by human limits.
I really think that if you want properly catechise someone regarding this rule of the Church, that the analogies should be comparable and make sense. But it’s up to you. If it works, and you get people to understand by your analogy, that’s great. But I don’t see how it can work. In fact, I never questioned this teaching until I came to this forum and heard all the ‘reasons’ why women “can’t” be ordained. I don’t buy it. It’s not a problem for me because I’m not in any way interested in entering religious life. But it certainly doesn’t make or break my day that women are pressuring the Vatican to ordain women. I’ll put it this way: when women get ordained, I certainly won’t be among those unhappy, that’s for sure. I would welcome the change.