Went to the gynaecologist's today for the last ultrasonogram; it's now definitely a girl, he says (and showed us the labia to prove it). Weighs about 2000 g (4 lb 6 oz) and would probably be around 3300 g (7 lb 4 oz) at birth. Dimensions are about average, with head size slightly on the large side.
Fortunately, it appears to have turned around finally; the head was at the bottom this time.
Stella was also on the CTG again; the baby's heart rate was typically about 150 bpm, with fluctuations down to 137 and up to 165. So everything looked fine. "UA" (whatever that is; seems to have to do with contractions) was about 20 at the beginning, slowly dropping to around 13 at the end.