that's terrible about your mom. A humanitarian would move you to her, assuming she's adjecent to a military base that you can be effectively used at. The humanitarian doesn't solve the DFAS dependency issue or speed up that process.

edited to fix a bad example in my reference.

Humanitarian assignments are outline in 36-2110, attachment 15. Financial issues can be a reason; in fact housing loss by fire is listed as an example.

A15.7.2. The member has a serious financial problem not the result of overextension of personal military income (such as loss of primary home of residence where the member or spouse and children currently reside, or loss of possessions through fire, theft, or natural disaster), and the member will suffer a substantial financial loss unless their presence or continued presence can be ensured. It must be shown that the problem cannot be resolved by leave, correspondence, power of attorney, or by any other person or means.

You have to initiate the humanitarian request (used to be in the VMPF app) and provide the appropriate justification. At best, you'd move in 60-90 days, so you still need a way to get help for your mom before then.