The immune benefits are still there too, and past two years they're likely to be in more and more contact with sick toddlers/preschoolers. My DD1 bf until almost four and six mths after she stopped she had her first (and only) ear infection. I don't think it's a coincidence. She's now 7 and that's the only time she's ever had to go to the dr for illness. I think bfing built her immune system to be as strong as possible.