When buying a bed for your little girl, we should think about the time for which the bed is to be used. How long you will need your girl to use that bed. If you want the bed to last till she turns 6 or 7 year old, then you can opt for small sized toddler beds.
When choosing a double bed, it is important that you try the bed with your partner, and that you both have enough room to stretch out. Beds should be 6 inches longer than their tallest occupant, but, if you have the space, it is better to buy a bed bigger than the absolute minimum size.