It is normal for her to swell and lick.. she is keeping herself clean.
I would keep them apart for 4 weeks. I had one to tie on day 24...better safe than sorry.
Are you wanting to breed your pekingese with her? I hope not..
I hope you have researched yorkie breeding. There is alot of heartache, expense, sleepless nights. You have to be prepare to lose your girl or the litter. Make sure you have the finances that go with it.. csections and raising a litter is not cheap.