APS in Placer County

is there anyone who has had experience with placer county adult protective services? my sister is stuck caring for her mother-in-law and trying to work pretty much full time. her husband and his brother (who is very wealthy) refuse to help out. she is afraid to speak up (husband is abusive). the m-i-l's house is a pig sty (they have completely cleaned it before, but it doesnt stay clean for long) and she constantly has infections. if i were able to contact aps without giving my name and report her filthy house, what would happen? i dont want to get anyone in trouble, i just want the m-i-l's family to step up. thanks.