The critical question here is: What has been happening for the past three months to her weight gain, growth, and energy levels? Toddlers go through food strikes when it seems as if they are living on air. Then they go through food fads when they eat only one thing for a couple of weeks and then reject that same food completely the next day.
I have a suspicion that the attention and concentration that you are expending on every morsel that passes her lips is counterproductive. The more you obsess about it the less she will eat. On the other hand, if she is becoming malnourished, has low energy levels, and is losing weight, there might be something wrong. In that case, see your child's healthcare provider. If you already have an appointment set up for her 1-year checkup and if she seems otherwise normal, wait until then to express your concerns.
I have to tell you that I see children who eat like this all the time. I think that toddlers go through growth spurts when they eat a lot and periods when they are consolidating their resources and do not need as much. Also, children often fall a little lower on their weight gain curve at about 1 year as they start to cruise and walk and expend more energy. If she is still running you ragged and seems bright and alert, there is probably nothing to do but wait until she starts to have more of an appetite.
Just be careful that you do not fall into the trap of giving her more and more milk just to make sure she eats something. Sometimes these children end up with excessive amounts of milk to the exclusion of other food because of parents' concern. She should have no more than 16 to 24 ounces of milk per day. For some children, a supplement such as Pediasure can provide some extra nutrition and in your case, give you some peace of mind until her appetite improves. Talk to your provider to see if this is suitable for your child.