Can my daughter stay at home for a few weeks before moving to a different school?

It shouldn't be a problem really. It'll be a good chance for her to get her mind straight. Usually if she's a new student the teacher would go easy on her and help her adjust to the class. She might be given extra homework or asked to stay behind after class to catch up on what she doesn't know. If they ask you at the office why she missed 2 weeks say something like "there was a family emergency", they'll back off and won't ask anything.

Consult the guidance counsellor or VP.

You can let her stay home its up to you. Just get a pre-absence form from the school and say your going on vacation. Or let her deal with it for 2 weeks so she doesn't get behind.

Personally, I think she should go to school. You do not want her to get behind in school. That would just make things worse for her. In addition to any social issues, she would become frustrated by being behind. This will give her a chance, too, to get to know some kids before the Easter break.

I understand the bullying issue and am glad you are transferring your daughter. But, I would not give her an additional 2 weeks of vacation. She will miss material she may well need to do well in her classes at the new school.