First of all , no debt collector can seize any property of the debtor without getting a court judgment for the debt first. Then the court enforces the judgment by means of certified bailiffs. Some debt collectors may be so certified, but they still must have a court judgment, and which empowers them to take goods ; the Court may not have ordered that because it may have settled for some other method of recovery. So rule one is don't admit them to the house and demand a sight of the judgment which empowers them to take goods as bailiffs.
They can't take any goods, even then, if they are genuinely told that the goods are not the debtors. In your case that will be patently true; your daughter is only a guest with few belongings.
What I expect they want is for your daughter or you to make them some offer to settle the debt without going to court. You have no obligation to make any offer and shouldn't; the debtor is your daughter and they are restricted to trying to get something from her alone, not you, and your making an offer only encourages them to try for more than they can legally get from her. You'd only be liable if you signed to guarantee payment when she incurred the debt, in the event she didn't pay i.e. as 'guarantor'
The public get misled somewhat by TV documentaries showing cars being seized. The cars will be under hire purchase or some credit agreement whereby the finance company can take the car if payments are not kept up; when they aren't, the company seizes the car. In law, the car didn't belong to the person who had the car and signed the agreement; it belonged to the finance company all the time until a certain number of payments were made.