How many coins do you have? It won't hurt to gamble some EC on batch rolls instead of single rolls (and you're already on the last round anyway) and see if you can get the last bloom.... but in order to do 50 rolls, you'll need 14,000 EC (a little over 4.5 days worth of stamina), and unless you do more than 1 gem refill, it's not likely going to happen. I didn't get mine until the 41st roll of Round 7, but I already got there 4 days ago.
You could do Ivan's suggestion for a short cut: farm life crystals and get a gold skillbloom, but if you don't feel like using the shop skillbloom on event girls, the [very] long cut method is to wait for her reissue event (ETA: 26 weeks from now?)