My heart goes out to you and to DD!! Our DS is 8 now, but he still takes a special "friend" whenever we go on a trip, and I still cringe at the thought that we might lose it!
This won't help with your DD and "Daisy," but maybe it will help others:
Way back when DS was very young, we started putting a harness and leash on whichever stuffed toy we were taking. We bought the smallest small-animal harness that we could find that would fit the stuffed toys and would either buy a small leash or make one out of ribbon and a snap clip. I used a laundry Sharpie and wrote our last name and phone # on the harness. Depending on which stuffed toy we were taking, we'd have to make some modifications in the harness so it would fit snugly. It makes it so easy for DS (and us) to keep up with the stuffed toy (esp. on plane trips).
DS has been in favor of the idea (sometimes kids don't want you to mess with their toys!), but then, we laid down the rule that either the toy got the harness put on, or it didn't get to go anywhere with us. I would recommend keeping the "leash" part short -- just long enough for a DD/DS to hold onto -- as a long, dangly cord could be a safety problem. Then, to prove to DS that it wasn't going to hurt his toy, we've had to do the "put 2 fingers between the harness and the toy" safety check.
We still use it, in fact I just unearthed the harness for our up-coming ski trip. It's been on everything from stuffed sharks, stuffed 3-headed dragons, Dumbo, Bambi, various stuffed cats, and even a stuffed snake (that one was a challange!).