I agreed with Cucaloco... if you dont mind buying a place and living there for a while, its a great time to buy but do your research in that area. Im from central cali, and prices are pretty low. I dont see it going any lower, as good price homes are being bought the day they come on the market. if you read on here, there will be many people saying wait wait wait... or buy buy buy, but take some time to think. i just lost my mother almost a year ago, and til today, its hard. Luckily she left you with some tools (cash and the house) that you can use for your advantage.
There are also other factors that plays into your decision, especially your credit. People on here, like Jon is going to give their opinions but they are not local and do not know your local market. There are also very negative people on here, just think before you act.
As far as your mom's house, I would suggest selling it also only because it is going to be hard to own it with your other siblings if you guys dont get along. Many seasoned investors will tell you that investing with family and friends are not that easiest. Im no expert, just a beginner investor so BEST OF LUCK and my deepest sympathy for you and your family.