I do believe that there was a study showing a
small excess of girls in pregnancies where the mother
was hospitalized for hyperemesis.

Only a small excess, which can probably be interpreted that it might be
different for different people, based on what hormone they are sensitive
too. I thought most of my sickness in my 2nd pregnancy (girl) was an
indirect consequence rather than a direct consequence of pregnancy, for
example it was more in the 3rd trimester than anywhere else, I think it
may have been pressure on my stomach and me not being able to gauge
fullness accurately and rather than get indigestion it just came back
out again! I do remember being sick in the 2nd trimester too, but it was
often early evening and often with no warning. Nausea wasn't a big feature.

Nausea bothers me more than actually being sick, though the being sick
this time has been worse than last time, I think because I'm often sick
after having had one bite of food, so I'm being sick on an empty
stomach, which hurts! I'd rather be sick with a full stomach any day!

Cheers
Anne