Bridesmaid dress altered too short - ideas on how to fix it?

So, I found this gorgeous dress for my sister in law at Dillard's for like...$40 on clearance. It fit her just right except it needed to be hemmed. She contacted me yesterday so upset because the person who hemmed it (who also did my wedding dress I'm not sure what happened) hemmed it like...four inches too short. You can totally see her shoes she says...and that it is even too short with flats on. I haven't seen it in person yet, I will on Sunday. So the dress has a couple of layers with a filmy layer on top and that one doesn't look crazy short in the photos but apparently the under layers are even shorter.

She is so upset and worried and I'm like, "we have two months, we can figure this out! I had a dress disaster come back four days before the wedding (literally could see the entire back of my bra in my dress with the bra I had been fitted in) and that got fixed - we can work this out."

She's looking at new dresses...I feel like with the time availability we should be able to do something about this. Any tips on how anyone solved a similar problem?

I'm thinking:

- attach a whole new layer underneath that is the right color and wear flats. Add lace to the front..?
- cut the entire skirt off and make it into a two piece
- she already tried to fold the top sleeves part down as if it was strapless to see if that would give it some length...no dice...


Thanks!