Territorial or normal bonding behaviour?

I am trying to bond my 18 month old female rabbit with her brother whom she has been separated from since 8 weeks. (Both are desexed)

The first two bonding sessions went well, no aggressive behaviour.

The last two days I've been getting growled at by my female rabbit whenever I try to pick her up and tonight I held the male while in her "territory" and she ran up to him and bit his head?

Their current living situation is my female rabbit in her normal closed off area with access to and from her hutch whenever she pleases.
The male rabbit is in his own hutch which has been placed in her living space but his doors are kept closed.

Do you think she is only being aggressive because he is in her territory or is this normal bonding behaviour, or could this mean she is unwell?

Please help, I'm desperate to have them get along

It's probably because he is in her territory

Bonding is best carried out in a totally neutral area. Females are more territorial than males and she is probably very unimpressed that he is trespassing!

There are loads of very good bonding threads on here. Happy browsing.