Agree with 33. I have been asked for recs by some women whose paperwork looked good but they had major personality problems that could really screw up a chapter.
As alumnae my mother and I have both been in the same situation in which we had to not recommend a pnm or contact the rush chair/advisor directly to share our concerns.
If you are not comfortable writing a recommendation don't do it or as suggested earlier, contact the chapter to withdraw your rec.