Before you offer her your boob, a few things to check to see if she's drinking when she latches on:
1) Pauses in between sucks and sounds of swallowing
2) Your boob is softer after a feed
Then if she cries when you put her down, try other things like carrying her and what-not. Sometimes she just wants to be burped or carried but a lot of mums will give her their boob first thinking that she's hungry and being a baby - ALL babies love to nurse - she'll definitely not complain!