#1 i put in 30kg. Everyone kept telling me to eat for 2. Pfft!
#2 i put on 10kg but lost it all the day after he was born.
#3 so far at 17 weeks i have actually lost 6kg so hopfully thats a good sign i wont gain much.
I think by 25 weeks I had lost 6kg & only ended up 3kg heavier by the end than when I started so I'd say you wont put much on overall. I lost mine over night too LOL I ended up being 5kg lighter than when I fell PG this time round. With DD I was 1kg lighter than pre pregnancy the following day.
I do think it has a bit to do with genes though so considering what happened with your #2 I'd say you have a good chance of doing the same this time round