Yesterday nearly 30 hours ago my 15 month old cockapoo ate a strand of tinsel, first we made her though up by giving her salt but didn't see the tinsel, so we are keeping a close eye on her she is acting fine eating well and playful as normal, she had bowl movements almost 4 times till now and we did not see the tinsel. I'm not sure what should I do. She seems to be fine, but should I wait and see for any symptoms or go to the vet? Any advice will be much appreciated.

By a strand of tinsel how much are we talking about here?

If she is still eating fine and having bowel movement (that are regular in color) I wouldn't panic.
If there was something wrong then there would be pretty obvious signs such as excessive drooling, lethargy, blood in stools, straining but not passing stool, loss of appetitie etc.

Tinsel can bunch up in the intestine and require surgery. Watch her and if she starts vomiting, get her to the vet immediately.
(vet tech 12 yrs)

After 3 weeks the dog would have either passed it or be dead.