Your friend owes money to people. She needs to face up to the consequences of her debt and deal with them, not leave you to deal with them and also face the anxiety of having HCEs seize your property because you are not able to provide paperwork to prove what is yours, is yours and not hers.
They don't have to give 7 days notice as said above and they don't have to wait for a second visit before they can seize goods.
Tell your friend that she needs to contact them immediately and you will not cover for her again. Ask her how on earth they traced her to your home and she has brought you into this mess.
Above all, she needs to talk to them. She needs to make an arrangement to pay. If she has goods which can be seized to go some way to pay the debt, that is only right and proper that they should be seized, but it is unlikely they will do so if she is truly on her uppers and it makes no dent in the debt. She needs to show them her position and what she could afford.
Does she now realise that because they have been called out, and will have to call at yours or somewhere else again, the debt has now increased? It will increase quite significantly every single time the HCEs will come out.
Urge her to call them today.