France does not perform same-sex marriages nor does it recognize same-sex marriages from other jurisdictions, but Liberation reports that a marriage between two women will be allowed in Brest as soon as one of the partners is legally recognized as a woman in December (sic throughout):
Wilfrid Avrillon, who's still considered a "woman in a man's body," married 43-year-old Marie, who's a lesbian, fifteen years ago. They have three children before Wilfrid decided to become a woman after an operation.
Her birth certificate should be modified as the process continues as it normally does for people who change sex. The tribunal did not ask for divorce before acceding to this demand, according to the lawyer. "There was no opposition. The prosecutor agreed, everyone agreed, and we'll certainly have a judgement December 15th that will rectify her civil status."
The prosecutor can still claim that it's a same-sex marriage and appeal.
Anyway, this is bigger here than it would be in the US.