Can I appeal a domestic violence restraining order in once it has been granted?
If the mother obtained a restraining order on behalf of her 18-year old daughter, it is likely the mother had no standing to do so on behalf of another adult. Furthermore, it does not sound like there was any contact between you and the mother except for one phone call.
Of course, it would have been best to have an attorney at the actual court trial if this case has already gone to trial. If it has not and only a temporary order has been issue, you should obtain an attorney immediately. However, if a permanent order has been granted, there is a slim possibility to reverse it. Your best bet is to file a motion for reconsideration, which must be done within 15 days of the judgment date. Said motion must be based upon new or different facts. You may also do some sort of motion to modify the restraining order if the court inadvertently included improper orders.
Anything from here on out, though, is an uphill battle. Your slimmest chance of all would be to appeal. This must be based upon an error of law. It sounds like your side of the facts were not presented.