As for me, this was one of the many things that stopped working in my game. Going back to an earlier save and retrying fixed it. The game is so sensitive. I save very often and have to revert back to earlier saves often. I am slowly making progress in my storyline. I think I may have problems with this neighborhood because it is heavily edited. It seems the more editing I do the faster it gets borked. Hopefully the game will get more stable. One can only hope.
Thanks for the advice. I went back to an earlier saved EA folder.. and reinstalled WA... and my sim EASILY (so easily that it almost pissed me off a bit) was able to go steady with Jean Luc in France AND had the option to propose marriage. Their relationship meter is only half-way full!
It was ridiculously easy. Let's see what happens when she comes back from France though!