Breast lift and fat transfer should not significantly change your ability to breast feed. If you have breast fed before and know your body has the ability to do so, you should be fine. If you have never breast fed, it is important to know that difficulty with breast feeding is common at baseline, with or without a history of prior breast surgery.
Anything is possible but it is very unlikely that fat grafting to the breast would change your ability to breast feed. Having said that the question is confusing as fat grafting to the breast only adds volume, it does not lift the breast. A traditional breast lift with scars around the areola can definitely affect your ability to breast feed.