I actually meant a male 500 deadlifter but we'll see. There are two scenarios at play and only seeing the lift would really allow one to hazard a guess. If she has a lot more capacity at the bottom and middle, and can learn to carry more speed through the lift while working on her lockout power you'll be right. What that basically means is that if she really is only lacking lockout power for 275 and through technique and some patchwork training can get through the lockout she'll make the lift, which is reasonable. The other scenario is that her 245 was a grindingly slow max rep the entire pull - meaning the bottom wasn't easy and her acceleration and technique was already maximized. In that scenario she might not even get 275 off the floor, no less have a chance to lock it out. Basically the entire chain lacks the capacity and needs to be increased so patchwork training and technique won't add much more than a slight increment and no where near the 22%.
This is like a guy who just barely grunts out 300 on the bench with spotters all around and the bar agonizingly slow and grinding the whole way and then expects to load and make 366 in 6 weeks. If it was super easy the whole lift and he wasn't going as fast as possible and just needed some tricept strength and speed to lock it out that's a whole different story. But a slow grinding rep with maxed capacity at all stages - that's a dramatic increase in strength throughout the entire range not just some patching and technique.
I'm hoping that the first case is correct for her but regardless she can perfect her technique, address her limiting points, and plan her training to chip away over a time period.
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Well you dishing out DL advice to hime please advice him that the 80's called and they want there hair cut back 
I wish I could blame the last attempt on the wrong outfit. 
