Question About Training A White West Highland Terrier, Approx 4 Months Old, & Weighs Approx 5-8 Pounds.?

Before I put her in her crate for the night, or if I will be out for a few hours, I always take her outside to do her business, & for the most part she is OK in the crate & will not have any accidents.
However, sometimes she does, & I know this is normal since she is a puppy & all – but my question is this – Sometimes I see her eating her Accidents! How do I make her stop!
I do leave water in her crate, a small amount but just enough to either last through the night or while I am away. I do not leave any food in her cage, I do feed her every morning & put out a little more than 1/2 cup of food with her water. I do spoil her with treats throughout the day, like when I take her out to reward her for going outside & such, but every once in a while I see when she has had an accident in her cage, & I have come home to catch her eating it!
Is this bad for her? How do I stop this