Well she's not a toddler anymore (she's 5) but I'll answer anyway
I answered 0-4 times a day but I also could have answered "as much as she wants". I use "don't offer, don't refuse", well, I usually don't refuse unless I have a good reason. I'm currently home with her (until K next year) so right now she nurses first thing in the a.m., once or twice during the day usually, then at bedtime. I trust her to let me know how much she needs.