Yep sounds very normal to me She's only little and at this age she will be doing alot of parallel play.... it's not until they are around 3-4yrs they start playing more with each other in role plays etc.....

My DD is 2.1yrs and is actually quite good at playing with kids but usually older kids! She loves the 3-4yr olds and that's probably because they tend to play more with each other than in solitary play like kids under 2yrs do. And DD loves playing with kids more than on her own, well most of the time. She loves company and is very social. I think it just comes down to their personalities really!

The more you socialise them, like playgroup, kindy, mothers group etc, the better at it they will be and they are all developing at their own pace too remember.

I love watching DD with other kids. She has a few close friends from various places (mainly playgroups) and talks about them sometimes at home.... like she'll say "and see Maddy today??" she just adores her little friend Maddy, I love it