Okay, OP... I agree with you that some folks on this thread may come across as a little, well, assertive in their tone.

But I have to agree that a 2 year old probably needs his/her own seat. I say this relunctantly but realistically. It doesn't matter how small/well-behaved/[fill in word here] your child is. Airplanes are crowded, there isn't a lot of room for passengers, much less for lap children. I do think it's unfair to encroach in other people's very limited space, and with a 2+ year old lap child I don't see how you could possibly avoid it.

So I say, buy the ticket and get her a frequent flyer number.

Now excuse me I must go post in the thread about seat changes for families.