rushing as a sophomore

Give it a shot. You will just have to accept that your options may be limited (I.E. only getting invited back to maybe 4 chapters after the first round while a lot of the other girls will be going back to 7 or 8) I usually won't tell people to not give it the ol' college try. If you really want to be a part of any of the sisterhoods UD has to offer then go in and give it your best shot. Use your improvements from freshman year as a positive rather than a negative. Put a positive spin on it.

I am in the same position. I didn't rush last year but I plan on rushing in the spring as a sophomore with a 2.9.

GPA is not the most important thing when rushing a sorority. Yes even with a 2.9 you may get cut from a few of the more selective sorority in terms of GPA but don't get to worked up over it.

GPA aside...
Despite what some people may try to tell you, everyone takes sophomores, just some more than others.
Please excuse my use of the phrase "tier" but this is a pretty fair breakdown:
10% of sophomore pnms will be placed in one of the 3-4 "top tier" houses
25% of sophomore pnms will end up in a "middle tier" house
and 65% of sophomore pnms will be in one of the 2-3 "bottom tier" houses
It's also worth mentioning that even if you don't get into a "top" house or whatever chapter you had your heart set on from the beginning, you'll still be social, have the same experiences etc. no matter what house you join. Everyone gets cut from one or more of their favorite houses, it's not the end of the world.