Yes it can be done, but very hard to explain in writing.  You need at least 2 and really 3 wraps of the pulling end of the rope around something very sturdy.  Ideally you have a long enough rope you can walk all the way back behind her and persuade her into the trailer taking out the slack all the time.  In a perfect world you bring the same rope back and run it behind her. 

Even easier, if you have a few panels, rope her and tie to trailer.  Then take your panels and build a pen round her so her only option is to go in the trailer.  Eventually she'll go in.  Absolute most dangerous part is getting the second and third wrap around whatever you are dollied onto.  Your arm/hand/fingers will be in the perfect place to get broken should she decide to back up.  You must have several wraps though or you cannot overpower a 1K+lb cow with the help of the friction of the wraps.