Hello and welcome to Just Answer.
Loperamide can be a safe drug to give to dogs, but there have been several reported cases of serious toxicities in dogs (especially in sight hound breeds like greyhounds and collies). Loperamide is an antidiarrheal which is typically dosed at 0.08-0.2mg/kg up to three times per day. For a 60lb dog this means giving no more than 2-5mg no more frequently than every 8 hours, so I would suspect your dosing was a bit high. My biggest concern is with her symptoms and her breed. Do not give her any more of the loperamide. Because loperamide is potentially a neurotoxic substance, it should be used with caution in those herding breeds (e.g., Collies) that may have a gene mutation that doesn't allow them to process this drug properly. Unfortunately, we just never know which dogs will have this mutation as on occasion non-susceptible breeds show up with it too. As a result I have chosen to avoid use of this drug altogether.
Symptoms of the toxicity include excessive drooling, incoordination, vomiting, hind end weakness, disorientation, stumbling, seizure, excessive vocalizing, hyperexcitability, hypersensitivity to noise, and coma.
If she is still acting strangely in the morning I would take her to your vet first thing. I am including a research abstract for you to print off to take along to your vet (in case they've never heard of this before because it is relatively uncommon).
http://www.vin.com/Members/Journals/Journal.plx?AID=1692 (you may not be able to access this article as it requires a special membership to a veterinary journal service, but your vet might be able to if you take them this URL).
Also, here's a handout sheet on loperamide for your records.
Usually intravenous fluid therapy (and in extreme cases a drug called naloxone) can be used to treat this condition. If she worsens overnight I would take her to an emergency clinic.
I really hope I haven't scared you too badly with all of this information but this can be quite serious and I need you to know to seek medical attention if she's not improving or worsening.
Good luck to you and your dog and hopefully this information was helpful!