I had heard Seb is difficult to "feed" and doesn't eat much vegetables but didn't know it had anything to do with allergies.
As for his wife I doubt she bullies him or she would not let him travel on his own so often, she would be behind him all the time like an abusive tennis parent.
It's a bit unusual for a guy to get married so young nowadays so in that respect, I would suspect she is somewhat influential on him. It reminds me a little bit of Sampras lovestory with Delaina, who was also older than him and also still studying.
But heck, so many guys marry younger girls, there's nothing wrong with the contrary.
I can only be respectful of the fact that she doesn't like being in the limelight but chooses to live her quiet life with her kids and studies.
I'm sure she's very supportive for Seb though, especially as she knows a little bit about tennis herself.