I purchased these slippers for a PUSH present.  She has a pair of UGG boots so I based the size off of them.  UGGS typically run a size smaller because there is no need to wear socks with ugg boots.  She hasn't stopped wearing them since she opened the box.  They keep her feet VERY warm and comfortable.  They are soft and feel  comfortable enough to accidentally wear them out as shoes!!! OOPS...  The bottoms are a nice rubber and grip nicely no matter if it is carpet, tile, wood flooring, concrete.  My own personal complaint but not hers is to me it looks like the fluffy part could come back around her heel a little further keeping more of her foot warm.  But I guess it is not a problem as she has not mentioned that yet.  Don't think twice about buying these, get em and she'll love you forever!!! Or at least until they wear out.....