In general, no. There is a myth that somehow breast milk undesirably takes the place of “nutritious foods” in older babies and toddlers. This is far from the truth. In reality, your breast milk is probably the most nutritious and “complete” food that your daughter is consuming. It is easily and thoroughly digested and is nutritionally dense.
Many children who are reluctant to eat solid foods in the first year of life later show some symptoms of food allergies. Her food aversions may be self-protective. Offering her a wide variety of nutritious food choices is vital, but having your milk there for her when she is hungry is very beneficial too.
The most important thing to look at with babies her age is developmental milestones. Is she meeting or exceeding these? Is she happy and interactive? If so, then it is probably too soon to worry about her size. Many toddlers go through this, and genetics can play a big role too — if one or both parents are smaller than average, then it's likely their baby may be smaller than average as well.
If your baby is not meeting appropriate developmental milestones, or if she seems withdrawn or listless, then it's important to follow up with a thorough medical check-up to see if there is something else causing these delays.