Short of going to Family Court where/who is the best place to get legal advice on dealing with an Ex-Husband?

my sisters ex-husband is ruthless, bad mouths her to her daughter, brings her back late from visitations all the time, sends her insulting texts, spreads malicious rumors, stopped paying child support, badmouths her to their daughters teachers - camp counselors -etc., refuses to pay his half for anything, family is worth millions but he pays no alimony and claims no income or ets (lives in a million dollar home), hares her boyfriend - even followed him and drove the wrong way on a one way street to confront him. What can she do? what are her rights? who can she speak to to get help? what type of lawyer? anyone other than a lawyer? THANKS!