Yes, her mother's name was Marie Antoinette
It was lucky James could not see Lily's face just then, because she looked very unhappy indeed that he was just going to ignore her. Again. She was sorely tempted to bring the subject back up, even after he changed it to baby names, but she reminded herself that she didn't want a fight...or, if she did want a fight, there were better things to fight about. Like how she'd been seeing Severus again. Well, not seeing-seeing, but talking to him...in their house....Yeah, that was definitely something that would warrant a fight. And of course, once she reminded herself of her secret, she felt terrible for keeping it from him, which made her drop the smothering argument entirely.
"I dunno," she sighed, relaxing. She slid her hands over James's on her stomach. "I was thinking maybe Antoinette, my mum's middle name? Do you have any ideas?"