Obviously she needs to talk to a lawyer & many give free consultations.
Most of all she needs to document any abusive behavior & all threats. She has to do that in order to protect herself & the baby legally especially if he gets even worse, which he's likely to do when he sees he's not going to get what he wants from her.
I'm not exactly sure where she was living prior to being in Calif, was that Fla? Her moving to Calif for such period may not have invalidated her residency where she lived before, so if that was Fla. She can still file for divorce sooner than waiting the full 6 months but I'm not a lawyer. It might be considered as an extended vacation to see if she wanted to make a permanent home in Calif but decided not to, at least that's a possible argument that could be made if she filed immediately (assuming a Fla residency before Calif). Did she change her driver's license to a Calif one?
I would suggest she talk to the local battered women's shelter. They are used to dealing with situations like your sister's & may have free legal advice available to her there. They will tell her what she needs to do in order to protect herself & the baby.
DivorceNet - Divorce Checklist and FAQ's
If I am a Florida resident but temporarily reside out of state, can I still consider myself a resident for purposes of getting a divorce?
That issue will be up to the Court, but if the Judge decides that you are truly a Florida resident, who is for example working for a corporation outside the state, or visiting elsewhere for a short period, etc. you will probably still be considered a Florida resident and can get a divorce. On the other hand, if the Court determines that you really have no intention of coming back, or that you realistically are permanently living elsewhere, even though you may travel back and forth to Florida from time to time, you probably will not be considered a Florida resident. Also, if you are in the military, the fact that you are stationed outside of Florida does not detract from your Florida residency.
What if my spouse is violent or harasses me?
In an extreme situation of course, the police must be called. Aside from that, in Florida there is a procedure for getting a restraining order if your spouse is guilty of certain conduct, without notifying your spouse of your efforts to get one. (consult the clerk of court or a lawyer) If the Court does issue a restraining order on this basis ("ex parte") there will be a hearing within a number of days after issuance of the restraining order where your spouse can come in to Court and defend himself or herself. This procedure can be used even before the divorce process begins. Once the divorce process begins, the Court can order your spouse out of the house if things are bad enough (especially where children are involved) as well as order your spouse to stay away from you. These matters have priority in the Court system and do not have to wait until the absolute end of the case. Under no circumstances should you make false claims against your spouse in order to gain advantage in your pending or anticipate divorce action!
Can the Court order something different than shared parental responsibility if my spouse is a danger to the child?
Yes. If the Court finds that it would be detrimental to the child for the noncustodial parent to participate in decisions concerning the child, then the other spouse can be given sole parental responsibility.