UK divorce laws - could Ellie divorce Joe without his consent to it?

This question came up on another board, so I thought I'd post it for discussion here.

If I was her, I'd have done everything I could to get rid of Joe Miller's name once he was accused of Danny's murder with pretty convincing evidence. But in series 2, she was still "Miller" (Millah in Hardy-speak). At the end of series 2, Joe wanted to come home or at least get his sons back in his life.

So does anyone know British divorce law well enough to know whether Ellie could get a divorce and retain custody after Joe was acquitted? In the eyes of the law, he's not a criminal. So he'd have to agree to a divorce and to give up custody of the boys. Or is there a way she'd have been able to get her freedom?

Frankly, I imagine Chibnall wouldn't want to change her surname because of the comic payoff of Hardy's pronunciation of it. It wouldn't be the same if he yelled "What is the point of you, Smith?"

What do you think?