Is it ok for baby to suckle just an hour after her last bottle feed (breastmilk)? It seems to me that she is using my nipple as pacifier (comfort sucking). But by letting her to do so, milk will come out and might overfeed her? She refuses pacifier.

Babies know when they are full when they turn away from your breast/ nipples. Usually, pauses in between suckles are longer when they are about to be full. Babies give cues during feeding that indicate how hungry they are. And to him, one cue he gives is going after your breast this time (after bottle feed) Maybe the pacifier's texture is far from that of the nipple that's why she refuses it? There are all sorts of different pacifier styles and materials that you can offer your baby. He might not like the first one you choose. Here's some guideline in choosing the 'best pacifier' for your child: http://www.consumerreports.org/cro/pacifiers/buying-guide.htm