My friend and her dad owned a house, his name and her name, he died with no will, who gets the house....

It will depend on how the property was held. If it were a joint tenancy, then it is hers on his death. If it is tenants in common or some other method, there may have to be a probate but you don't really say anything about that or whether there are siblings or a spouse. Easy enough to get an answer though and you will want an Oklahoma attorney if that is where the property is. Use the .com to find an attorney in his/her area. In addition to that, contact the local bar association for referral to an attorney who specializes in this. Often, but not always, the attorney will do an initial consultation free of charge. You will then be in a better position to determine what to do next. Best of luck to you!

Ms. Johnson gives you good advice. I just wanted to add one quick point. If the deed states the two names followed by the words "as joint tenants with right of survivorship," that signifies that the property was jointly held and will (subject to certain limited exceptions) go to the survivor upon the death of the first. If, instead, the deed states "John Jones and Mary Smith," that would signify a tenancy in common and the interest in the property of the first to die will vest in that person's estate. My reference to certain exceptions is that it is not clear from your posting whether yur friend's father was married at the time of his death. If he was, his wife will have a "right of election," which, in most states would entitle her to one third of the estate. Good luck to you.