Ds2 is 8weeks old we didn't want anything huge as just before Xmas so got Ds1 aged 4yrs a orchard toys game he could play with us at hospital at a set of 3 books he had wanted for a while and I read him them as his bedtime story when visiting me as I was in 2 nights planned section.
Camera is a good idea - she loves taking pics with my phone - but for an under 3 y-o I guess a toy camera not one that really works!
DH thinks it should be an actual toy for her to play with rather than a keepsake, as for him it's a transitional thing to keep her occupied during the weird new baby time. Left to me myself I'd buy a jewellery box or something I think!
I think the best present to get is anything they would enjoy the most. I got my DD1 aged 2.10 a pram, babyseat, highchair set for her doll when DD2 was born. She was completely indifferent to both her doll and the real life baby. I should have bought her some more matchbox cars for her wooden garage as that was what she loved at the time.
They are the absolute best of friends now.
I think the camera idea is a good one. The V tech ones don't take brilliant photos but they're very robust and good fun.
My dds were very capable of using a kiddizoom camera before they were 3 if you do want a real camera. I really like seeing the photos, it's like a little insight in how they see the world and what's important to them!