Perhaps she just hates the job and the store now and is unhappy with life and it has nothing to do with you.....
personally, i don't think it has anything to do with you or the other regulars... it seems more like something in her personal life that may be bothering her, which often causes people to withdrawl from daily interactions, even with friends and at work....
In any case, if it's really bugging you... you could adress it and ask her what's up?? or ask her husband and see if anything is going on?
But myself, at our store that we go too, i know a couple people... but for the most part i don't care if they want to be my friend or not... i'm there for a the business and to get my items, not to make friends.... but that's me... some people would probably call ME a fridgid bitch because i have friends and i'm not interested in making more, this gal might be the same way...
at any rate, i wouldn't take it personally if i were you
Sweetpea