C.E.
Hi M. - I am speaking from the perspective of having nursed three babies. The two youngest nursed until they were close to 2 - and much as your daughter - it was a comforting way to nap and go to bed at night. I wouldn't force weaning her away unless you are ready. Those sweet moments of nursing only last a short while. I did have to distract my son when weaning him at about 22 months, but my daughter who had slowed down considerably by 20 months just finished nursing one day and said "I done" and she meant it. That was the last time she nursed!
If you are ready, doing another comforting activity like reading stories or snuggling with a favorite lovey item can help the transition.
Best wishes to you.
C. E.