Bed for toddler

My LO will be 2yrs 1month when the new baby gets here and I know she’s little, she’s currently in her crib. I don’t want to spend money on another crib, instead I was planning to get her a floor bed with rails and use the crib we have for her little sister. I do have a bassinet which I plan to use for 3-4 months that’s what I did with my daughter. Idk when I should get her the bed? should I go ahead and get it now and transition her to the bed before the baby gets here or should I wait since I do plan to use bassinet and it will give us a few months? Is that age appropriate to be in that type of bed? I’m due in March and I’m a little afraid of everything including this decision and the transition to her bed. And honestly just the transition from 1-2 in general.