Yes, it is something she should be  concerned about: she will be paying a lot of money and not getting the property right away. If for any reason the recording is not done the next day, she will have to bring a legal action to compel it. If they want to close on the 30th, it should be recording on the 30th; if the sellers need another day to move out, she can give them a use-and-occupancy agreement giving them the extra day (either with the paying her "rent" for the day or--if she doesn't care about one day and wants to be courteous--no "rent"). But your daughter should own the house the day she closes.