They provided the ovum, they are the mother. Not a father.
This ridiculous semantic gymnastics has to stop. The rot set in with the GRA of course and the existence of GRCs. If the original legal fiction hadn't been created, this wouldn't be an issue.
Poor child. Also, I wonder what 'gender it has been assigned' on the certificate or has the parent thrown a wobbly about that as well? I mean how can they actually know until the child turns three or so and can start choosing sparkly clothes or not?