alot of questions.....really need help

My mom had a policy for several years where she made payments each month, she had a $50,000 policy. A couple of years ago she started a new job and took out an additional 50k, my brother and I are the beneficiaries of both, that was in july 07, she worked at a hospital and always had bronchitis so she was always getting xrays done every few months. In May 08, they found a spot on her lung and suspected lung cancer, sent her to a charity hospital. to make a long story short, she had lung cancer and in march 09 passed away. She was with a guy for several years that we really didn't approve of, but my mom was the type that you didn't tell her how to live her life. Well after they found the cancer he decided he would finally marry her and made her change the beneficiary to half him and my brother and I would split the rest. ( i didn't find out till after she died he physically abused her at times) She did that in June 08, and he took out a life insurance policy on her at his work and said she was healthy. he was getting 20k off of that, (which i thought you couldn't lie on those but he did anyway) well my mom finally got enough of his bragging about how much he would make off of her death, and in september 08 called and requested forms to change it back to my brother and I, it took her a month to get those forms and she changed it back in october 08, on her own, she was not on powerful pain medications then she was still driving herself back and forth to radiation and even drove up to the lawyers office to have the insurance forms notorized herself. She was so happy. One day he comes home with an increase insurance request form from his work, he tried to increase his policy on her 60,000 to get a total of 80,000 off of his policy, he tried to force her to lie, but when he left she changed it, he was so happy ( at this point we were told she had 6 months to live that's why he done it) he kept saying he was making over 100,000 off her death, he would even say this to her, he told her he already had another woman, and when she died, he was going to fight her kids (which is my brother and I) and make sure we don't get a dime of her life insurance money. My mom didn't tell him she changed it cause i believe she was afraid of what he would do to her or us. So here's what's going on. We told him after she died she changed it, he told us that he would get us we would be sorry. We sent in a claim form and the insurance company gave him one also, and he sent it in and said she was incompetent or under duress or cohurssed (sp?) My mom knew everything right till the end she was never out of her mind, she was telling jokes and being herself right till the end. She even signed her own DNR, two days before she died. Well the insurance company sent out a letter saying we needed to send them doctors notes saying she had a disability about three weeks after we sent in death certificate and all the claim forms. they guaranteed the payout of the first 50k but are contesting the other 50k (which i understand that) well in may they sent something only to my brother saying they needed her medical records from the hospital where she worked. a month later in june, they sent me the same papers, when i called and asked why did it take so much time to send them to me they said they never received my brothers papers, and i asked about when they would payout the guaranteed 50k and they said that when they are through with their investigation on the 2nd half then they will decide if my moms husband has any right to it, and would have to go to court. they told my brother they don't have to give us a time line on when we will know anything. so i'm looking for any advice i can get, any help would be appreciated, and also in april we found out from a lady that is over the insurance where my mom used to work that they have the other claim that my moms husband filed and that we will probably have to go to court (the insurance company never told us anything about this and still hasn't in writing) My mom had everything done legally, i'm not understanding how they will just believe him. thanks so much for listening, sorry so long. thanks again.