The relevant ethical rule says that a lawyer who's likely to be a witness can't represent a client "at trial." But the Court of Appeal holds that, notwithstanding this text, the lawyer can also be disqualified from pretrial proceedings as well; i.e., completely disqualified.
The underlying case is definitely a messy one. The lawyer is representing her adult daughter against her ex-husband claiming that he molested her during the early days of their 17-year marriage, whereas the husband claims that this is just a made-up charge to create leverage during a vituperative divorce.
The ex-wife/lawyer represents her daughter on appeal. Interestingly, although that attorney lists her address with the State Bar (and on the docket sheet) as the address for Phillips Jessner (a family law firm in downtown L.A.), that lawyer doesn't appear on the firm's web site. (To be clear: I'm not saying she doesn't work there; the firm simply doesn't seem to have elected to put her on its list of attorneys, at least presently.)
Regardless, it's a holding to remember: You can be DQ'd entirely if it's likely that you'll be a material witness at trial, at least in a situation like this.