I would say those and many other questions may be best answered by your vet. They can give an idea on age. Vets tend to spay/neuter at different ages. The vet we use, does work for many local rescue groups, so she may spay/neuter early compared to some.

Also, your vet will have ideas on when shots should be given, you may use the vet to give the shots anyway, although my fiancee gives most shots to our pets, but a rabies shots has to be by a vet.