Unless there is a reason she needs to be sleeping in a big bed (ie. a new sibling will need the cot; or she is able to escape from her cot; or other safety reasons) I can't really see what could be beneficial about putting such a young toddler in a big bed.
I would think that it would just be much easier (on the parents especially!) to keep her in her cot.
Its up to you of course, but its likely to be more disruptive as she gets used to it, plus she will always be in and out of bed, and nothing you can do about it!
But then again, I havent experienced this myself ... so maybe its not as hard as I think it would be, LOL
Aidyn is very nearly 2, and still in his cot... and I plan on keeping him in there for a minimum of another 6 months.