Open Question: Can I doing anything about a Stalling sibling on inheritance forms?

One of my husbands siblings are purposely stalling on turning in certain annuity and ira inheritance forms that require all siblings to send in paper work in order to close the accounts. These accounts are being effected by the Stock Market until the sibling decides to turn in her paper work. She is holding off because she makes too much money and the inheritance would make her tax bracket at 50% if she takes cash. But she has already said that she is just going to keep them in the annuity and ira so that no taxes get taken out and She is still not sending the forms in. It is bothering me because I think she is doing it on purpose. Me and My husband do not have a home. We live in a bedroom of my parents house with our 3 year old and we told her with the inheritance we were going to use it as a down payment on a house but we don't even know what kind of loan we could get until we have the money for down payment. Then she and my husband got into it about there parents possessions (she want them all because she is older) and he said to her that he want nothing anymore and that he was through with her. She cried then got mad ( she still took most even thou there is 5 children involved). We are starting to think she is doing this out of spite. My husband is not the only one who could use the money soon, one of his other siblings spouse unemployment is running out and that sibling does not know how they are going to make it without loosing there house. Is there any legal things I can do to get her to send the forms off? I live in California if that makes a difference?