You can try having her learn to ride naturally the way Europeans have had their children learn about as soon as they can work.

Start with a balance bike (no pedals). You don't have to buy anything, just remove the pedals from hers. The key is that she has to be able to put both feet firmly on the ground while seated on the bike. Find a shallow grade with room and no traffic (parking lots are good as are dead end streets). Let her practice walking then coasting, until there's solid balance and confidence. Then raise the saddle a bit to encourage the confidence and longer coasting intervals. If the bike has hand brakes, move to free coasting on longer slightly steeper slopes.

Once you and her trust the balance, the pedals go on, and she's a bike rider.

If the balance doesn't happen, go for a trike.

BTW- I've taught dozens of adults how to ride this way. The key is to overcome the fear of falling, so a low saddle and sure footing are the keys.