how can I change my 5 month olds sleep schedule? (get her to bed earlier)?

My 5 month old baby has a definite pattern, but I'd like to get it earlier. She wakes up around 9:30/10 naps at 11 and at 3/4 for 30 minutes to an hour each nap then usually does a tiny nap somewhere around 8/9. To bed between 10-11. Nurses at 4:30-5, nurses at 7:30 (these two are pretty predictable). It works well since I am at home with her and my husband works late, but I'd like to have her to be at least by 9. I've tried putting her down earlier each night, but she still ends up just going to sleep at the same time no matter what I do.

She never cries and always wakes up very happy and alert.

Any advice?

(She is only breastfed at this point. I'm guessing once we introduce foods at 6 months like the APA suggests, she might sleep longer. I'll only introduce food earlier than that if she is showing signs, so far so good, so three more weeks of nursing only.)