^ way back, like nearly 20 years ago, the 10 families rule actually meant 10 biological mothers. I know this because a lesbian couple who both wanted to use the same donor had to wait and see if the donor's limit had not yet been reached when they were ready for their second child (with the other biological mother). They were lucky and it hadn't. They were not allowed
under the rules to reserve sperm for their family for use by the 2nd woman.
This means that bodmin's ex would, biologically speaking, not be starting a new family.
However, since civil partnership and marriage laws have changed since the time I am talking about, it is possible that HEFA rules have changed. I have a suspicion they may not have.
Bodmin, my sympathies on the difficult circumstances and I echo Sherpa's advice. Get thee to a solicitor.
And I hope that things go better for all of you soon, however this turns out. It sounds unpleasant and stressful for all concerned