Yes, you can feel follicles. Considering you know what you are feeling. If your snake has had a meal within a week, it can be the meal still in there. I have felt follicles on my females 1000 grams or less as well (these were over 1 year old). So I don't think size matters much, as long as they are healthy enough they can develop follicles. This is my experiences.

Follicles are normally the same size when you feel them and they are one right after the other. They start about mid body. So when you feel for them it will be like bumps in a row not spread out or anything.

A good question is if they have follicles should you breed them regardless of age/weight? Health issues? anyone anyone.. hehe
Maybe I should start a thread on this..