11 month old weaning?

How do you know when baby is self weaning? My LO has always nursed at least 15 minutes and now will only go maybe 5-6 mins tops. This has been slowing down over 2weeks or so. She also has cut back on how often. I always try to bf her first before offering solids so I know it isn’t that she is full. The only nursing session that has stayed the same is right before bed. Is she slowly self weaning?