Did you inquire your friend about that toy? If not, do it casually and get to know about it. We should first know what it is.. Where she bought it.. Or who gave it..
If she has bought it in some local shops, there\'s nothing serious to worry. If it has been given by some Tantri after doing some Mantra/ Tantra works, we gotta think little serious about it.
If it is bought from some local shop, then she or her house might be under severe Evil Eye and that Slipper / Monster Toy must have observed them without allowing them inside the house. Since you touched that, the negativity must have just reflected to you.