Your daughter is tired, you put her to bed, she finds a way to settle herself down and get comfortable, she's not unhappy, and people are criticizing you?? Forget it! "No one can make you feel guilty without your permission." I forget who said that - Eleanor Roosevelt maybe? You have found a way for your daughter to self-soothe, a really critical skill. YOur alternative is to constantly stimulate by playing with her because she's still technically awake, even through she is cranky - she's telling you she's DONE playing and being stimulated, and you are responding to her needs. You cuddle, wind down, and then let her do the rest of it on her own. Now compare your baby, who can settle herself down, to all those kids other moms write in about to Mamasource, who haven't learned to do this yet, and the parents have to go in 50 times a night, keep putting toddlers back in the bed, and everyone's exhausted! Which life would you choose? Don't you go to bed, relax for a while, try a few positions to get comfortable, and then fall asleep? Would you rather go up every night totally exhausted, because you waited until you were completely dog tired, and then fall asleep before you head hits the pillow?
You are doing fine, but you just don't know it yet. You obviously have great instincts, you are "reading" your daughter's signals perfectly, she's not crying or hysterical, she's content, and your only problem is your mother and some friends. When I had my baby, he didn't come with a user's manual, so I had to figure out this stuff by myself! And his schedule wasn't the same as everyone else's.
Get used to the criticism or just brush it off with confidence - you're an ICU nurse so you're highly skilled at recognizing critical needs in others. I think you would know if there was something awful going on! Instead, you've identified a need in your daughter, and you've addressed it!
When your daughter gets a little older, you'll get a lot of pressure to put her in endless activities - so there's always going to be that comment about why don't you do it this way or that way. We got a lot of pressure to sign our son up for soccer, karate, piano, and so on - an activity every day. Aside from the cost, we didn't want him become the kind of kid who needed others to provide constant stimulation. He had religious school and ONE activity - sometimes he picked soccer, sometimes basketball, and so on. He tried different things, and he had a lot of time to play with neighborhood kids in pick-up games, create stuff in the sandbox, ride his bike, build things with blocks and train tracks, do crafts, read, and other things. Today, he is a creative and interested kid, passionate about one thing (running) but highly adjusted with lots of friends and a ton of confidence. He's an independent thinker because we didn't put him in situations where everyone else told him what to do every second.
All I'm saying is, you're going to have 18 years of people telling you what to do - but you don't need to lose your way here. It's FINE to ask for ideas and find out what other people do, but then you filter those suggestions and choose what works for you. Your daughter is not going to go to bed at 5:30 when she's 2 or 7 or 15. This is right for this time in her life, so stick with it!
Good luck!