I would not put a plant on the countertop. It's not large enough to have "dead space". Once she moves in, your daughter will need every square inch of counter space.
I second the suggestion about the shower curtain. With the soft background of the bathroom, your daughter can be very expressive, both in color and design, for the shower curtain. And then when she gets tired of it, easy to change and "update" the bathroom.
For a little girl:
For a bolder look:
For a fun look:
Q
Door casing
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