I've noticed that my 10 month old has been having pale yellow stools. Her diet has not changed except that she has been given some regular milk. Could this be causing this? I'm very concerned.

if it is just the poop and not also the skin or whites of the eys that turned yellow it is the milk! Poop has the amazing ability to come out in all different kind of colors, depending on what kids eat (give them beets and their poop will be red, give them green popsicles and you'll find green poop)
But if her skin is also yellow you may to have her liver function tested...
Seeing that the only thing new is the milk I would assume it is the milk that turned the poop yellow. Wait a few days and if you are still worried, go see the pediatrician (better to be safe than sorry...)

Karen