I'd definitely think a more familial relationship could work between them! I appreciate Jesper's love of all people, but I think they're better off not going that direction!

Nebula WILL be becoming closer to the Doctor during that time period. Some weird nebulous morons who ??? Don't know what feelings are??? I think part of her will never get over sulking and inaction so in between looking after him she could keep an eye and be like :/ :/ Seriously. Just get up and do something already!!!