What a lot doctors these days will tell a mom (and LLL supports this advice) is to *supplement with expressed milk.* This doctor needs a copy of a LLL book, to educate him about the benefits of breastfeeding. La Leche League is recognized by the World Health Organization and the American Academy of Pediatrics as the foremost authority on anything breastfeeding related.
Judging by her 6+ wet dipes a day, she's hydrated enough.
As for milk, yogurt, etc....It could very well be that her little body is not ready for cow milk. Is there a history at all of dairy sensitivity in your family? There's no dairy stuff in my family (or dh's), but neither of my kids wanted much to do with cow dairy until closer to 15mos.
As alternatives, we did goat's milk, rice milk, and -- after 12mos of age - almond milk.
Since you're in good ol' Texas, keep her water handy at all times. Especially this summer.
As she gets older, one idea is to get a fun 'new' sippy or bottle (not nipple, think sigg or kanteen) -- one that has fun animals or designs on it. It's possible that she's a bit young to care, but it's a thought.
HTH
K., mama to
Catherine, 5y
Samuel, 2y
EDD 9/09