Ok, please don't shoot the messenger, but if mother is not under any type of mental Disability or a guardianship, then she can choose to spend her money to help out sister without any legal repercussions. Although it may not be prudent for her to do so, there is no legal method for keeping a competent adult from spending their money how they choose to.
.
However, if you feel that sister is forcing mom to do things she doesn't want to, this may be considered "undue influence" and possibly elder financial abuse. You could file a formal complaint with one of the agencies that works with the CO Attorney General here:
.
http://www.coloradoattorneygeneral.gov/initiatives/consumer_resource_guide/elder_issues
.

.

.

Thanks.

Barrister

.

If you need further help please do not rate 2 stars/faces "Helped a little" or 1 star/face "I expected more". This is considered a negative rating against me.

.

Just reply to me via the “CONTINUE CONVERSATION” or “REPLY” button with the questions you have as I receive no compensation for my efforts for the lowest two ratings.

.

Please keep in mind that I am trying to help you understand and resolve your situation. I don't make the laws, I am just reporting or interpreting them, so the outcome may not be what you had hoped for.

.
Please be patient as I am typically working with several customers at any given time. Some answers take 5 minutes, some 35 minutes. But rest assured, I will get back to you.

.

Please be aware that I am not entering into an attorney client relationship, this is a public forum, and all posts are available for public viewing. There is no duty of confidentiality that attaches to any posts. With that in mind, please do not post any specific information you do not want available for public viewing. The information provided is not a substitute for a local attorney’s legal advice.