No one should have clipped your budgie like that - that said, it's hard to say what is better to do. Some birds can learn to compensate for being unbalanced and, if so, it's probably best to do nothing and just wait for her to molt and regrow the feathers. If she acts clumsy and unbalanced and can't control where she goes after an adjustment period, then you might want to clip her left wing a little bit more to help balance her out. But clip as little as possible to balance her - you don't want to remove any more than absolutely needed to let her balance.
If she is clipped too much, she will just fall like a rock and it won't matter if she is balanced or not.
My little budgie Winter came with most of her primaries on both wings clipped; even though it was a balanced clip, she was clipped so short she would fall like a rock if she slipped (she liked to climb to her highest perch and swing by one toe just to scare me). She injured herself one time, damaging the skin over her keel; it caused no visible wound at the time but became infected later and required a vet visit although it did heal up well. Budgies are lightweight strong fliers so falling related injuries are less common than with other birds, but still possible.