Am i spoiling my baby by letting her nurse whenever she wants?

My daughter is 7.5 weeks old and I've been a firm believer in nursing on demand. Her routine lately has been nursing every 1 to 2 hours. Sometimes it's less than an hour (when she's awake) and sometimes it could be as long as 3 to 4 hours (nighttime sleep). However, I've noticed lately that she has been using me as a pacifier. She'll suck for less than five minutes then fall asleep or she'll often wake while she is sleeping looking for my . I've been trying to get her to use her hands, but that hasn't worked yet because she is still working on her motor skills. I've given her my finger before and that sometimes works. I'm hoping some of you out there have had the same issue. She is still very young. I'm at odds about what routine/protocol to use when it comes to nursing her. Not to mention how much milk she is taking in. In about 2 weeks, I'm going back to work and she won't be able to do that anymore. I don't want it to be an abrupt change for her. What can I do to ease her to a steady routine so that when she is with the sitter, it'll be more set on what she is supposed to have?