we had no probs with DS going into the bed at night, now 4months on he still hasn't come out once...just luck I guess. But your DD is much younger & may not understand aswell so I would put the cot up also. I found my DS was not really worried about moving at all, a new adventure really so I would give the bed a go....something new to explore. But I would also put the cot up, if you are met with a battle you don't want to be wishing you had done it mid way through the night. Also I wasn't ready to give up arvo naps...so we left the cot up & he had them in there for a few weeks til he adjusted to it.
Also if you set the cot up too it will make things seem familiar & give her a choice. If the bed stresses her out you wont make it worse by not having something else to offer IYKWIM.