Definitely. Contact with the hip bone can lead to bruising at the least. With repeated contact I'd worry about a stress fracture. Following everyone's advice will likely eliminate any discomfort or concern. Work on posture--get the shoulders inline the the hips (or actually--get her hips squared to her shoulders) along with loosening up the lower arm and allowing it to whip. This will put the hip bone into a position where the elbow can tuck behind it and the forearm can wrap/roll/brush underneath in the soft spot above the thigh. Here's the shot that sluggers posted above:Is there any fear of injuries when encouraging her to contact her hip?
Here's a nicely summarized javasource video that Dave Mccrakin from The Fastpitch Zone put together: https://www.facebook.com/phil.mccrakin.1656/videos/2258610601062950/
Like javasource suggests in the video, get the hips squared to the shoulders by getting up on that back toe going into release. Looking at the pitchers in sluggers' picture, you can see that most are on the point of their drag toe.
Try this experiment: get into the release position with the drag foot on its side and just let your throwing arm hang down at your side. Then--not changing anything else, roll up onto the drag toe. Notice what happens?