Could Extreme Speech With Mood Swings In An Elderly Lady Indicate Depression?

So this maybe silly, but I m worried about my mom. She is 76, and her personality seems different. She talks non-stop, and sometimes says rude and thoughtless comments. She was an RN and has been retired for several years. She is used to getting by on little sleep, but even now she stays up till 12, and is often up at 5 or 6 AM. She lives about 5 hours away, and so we see her maybe one time a month, and have noticed her non stop talking. She also had many friends and now has a few. She has a kindle, and plays words with friends a lot. She probably has 30 games going, and two are with me, she wins 90% of the time. Do I have reason to be concerned about her? My Dad doesn t say a lot, but recently in the car told her to stop talking, and her feelings were extremely hurt. So much, that she wouldn t get out of the car to see her grandchildren after traveling 300 miles to see them. She sat in the car, and cried and pouted. She is lonely when she is at their lake home, and most her friends are at their old home. I m not sure how to approach this, or if I need too. I m wondering if depression is an issue? Thanks, Jolene