In England, legally, you own whatever share the deeds say you own. If your name is on the deeds, you own whatever share the deeds say you own. It does not matter who paid for the house, where the money came from, whether it was inheritance, whether she “intended” it to be hers, & whether she now regrets it
Property law doesn’t care about feelings, hindsight, or moral arguments. It cares about legal title. If the deeds say:
- Joint tenants → you own 50%
- Tenants in common → you own whatever percentage is recorded
She cannot simply “take it back” because she changed her mind. It doesn’t matter that the money came from her dad, she chose to put you on the deeds, and that made it a gift. She can’t undo that now because the relationship ended.
It’s very straightforward: if you’re on the deeds, you own your share. If she wants the house back, she would need to buy your share out at market value.
Morally it’s more complicated and this is not your finest hour but unsurprisingly that is not what you are asking about. Get a solicitor to confirm your position