I remember reading on a forum when my children were toddlers that the best things to give children are either real tools and materials, or toys for open ended play. It really stuck with me, and it's made a big impact on our lives. Will share some of the things we bought (much of it second hand), in case it gives some ideas.
My daughter is nine now, but at 5 her favourite things were
Playmobil,
a hammer and nails (and a comb for holding the nails so that the child doesn't bash their fingers!),
a small saw and sturdy work glove,
a play kitchen with a till,
a wooden train track
a sturdy children's spade for digging in the garden.
Over the years she's been given a whittling knife, child size secateurs, clay, knitting needles and wool, sewing materials, a hand drill, planks of wood for working with, and various screwdrivers etc.
I really think that buying her these 'real' things has made such a difference to her confidence and skills. At nine, she now competently uses a number of workwork tools, and looks after her own vegetable patch in the garden. She's good at problem solving, and will help fix things in the house - she took apart our vacuum recently and replaced a broken part 
. It's been interesting watching how these activities have given her a sense of satisfaction and confidence, and I often wonder how the advice I read on that forum will influence her life in the future!
So I just thought I'd pass on what I'd read in case it helps 
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I'm sure your daughter will be thrilled with her bike!