You're definitely not a bad mom, but the time comes eventually (sooner or later) for every mom to put their little angels in their own beds in their own room. It's not going to hurt you any less down the road, and definitely not your child. I can't tell you how many people (including myself) realized how much better their children slept after moving them to another room and how bad they felt for not realizing that sooner. I have 4 children, 2 of which were like your little girl and would curl up to the side. I used toddler beds on all of my boys (my girl is still a baby). There were a few times when they would fall off, but they were so close to the ground, it never bothered them. I also never ran in to help them at every call, cry or sniffle (and still don't), and they're perfectly happy and loving children (in fact, everyone is always telling me how happy all of my children and babies always are). They don't feel a lack of love or attention, and we've only had 1 trip to the hospital so far (knock on wood), and that was because someone that was holding one of them dropped him on his head. All of my children were in another room by the time they were 4-6 months old except for my princess. I didn't have her in her own room because we moved and our room is FAR on the other side of a long house from the kids' rooms. We kept her in our room until she was 8months old. None of us were getting full nights of sleep until we decided to move her. When we moved her, she had the first full non-awaking night sleep she'd had. I've known several people to wait until their children were 2, 3 & 4 then realized after moving them that they had been doing more damage to their children than good. At the other house, when the kids were across the hall, I didn't even use a monitor after the first several months with #1. I don't use a monitor with the others (even after moving into the new house), except for the baby, and I usually use a video monitor with the sound turned off. Every now and then, she'll wake up crying in the middle of the night (she'd go right back to sleep within a few minutes), so we started turning the sound off at night (if she cries for a long time, one of the boys would come and get us, but that's only happened a couple of times when she was sick).
I'll also add that I started off being completely in attachment parenting, but the sleep thing just wasn't going to happen. I slinged and pouched my kids, I cloth diapered, I home school, etc, but I realized that my children sleeping with me or even in my room until they were 2-6yrs old just was not what was best for any of us. If other parents want to do it, and it works well for them, great, but I have realized from my own experience and that of my friends, that the younger they are when they are made to sleep alone, the easier it is on everyone. I don't feel there's any right or wrong way, people are different, but this my experience.
Good Luck!
K.
SAHM of 4 (6,5,3 & 11mos)