Hold her down. I had to do it with my nieces and nephews. Wrap your legs around your childs legs, use your upper arm to hold her arms, squeeze her mouth open, pour the Tylenol in her mouth. Then blow very lightly in her face. By blowing it will force her to take a breath making her swallow. It sucks but its the only way I got my nieces and nephews to take medication at that age. Mixing it in their sippy cups never worked because they wouldn't drink it. But try mixing it in something first before resorting to holding her down.