If she's seeing a doctor because she's pregnant, that's an obstetrician -- who she may refer to as her OB or perhaps her OB-GYN (since many doctors are both obstetricians and gynecologists).
Yes, many OBs do ultrasounds in their offices, although detailed ones (generally done only once a pregnancy, about week 20 or so) are often done in offices devoted just to that. The average OB will have a simple, relatively low-end ultrasound machine -- good enough to check that things are proceeding normally, but not to get a detailed look at everything. (The kind an OB would have is called Level 1; the kind an ultrasound diagnostic center would have is Level 2.)
A fairly detailed site on obstetric ultrasounds. Answers to many ultrasound questions.
