What you want to do is qualify Dottie as a "service dog." In the US, a service dog is a legal term defined within Americans with Disabilities Act (ADA). A dog can become a service dog when it meets a few requirements. First of all, the service-dog handler must have a disability as defined under the Act. Endocrine disorders (diabetes) are listed in the Act as a disability. Second, the dog must be trained to provide a specific service that mitigates the handler's disability. Blood glucose alert, both low and high meets this requirement.
The ADA does not require that the dog be professionally trained. It allows for owner-trained dogs to become service dogs. Having said that, there are a lot of self-trained dogs that fail to meet the standard for service dogs. Most of these failures fall under the ability to calmly and appropriately cohabit human environments where canines are not normally present. A doctor's office waiting room is a good example.
A true service-dog can provide its disability-mitigating task in any environment that his/her handler occupies. That includes work, school, doctor's office, dentist office, grocery store, restaurant, bus, train, or airplane to name a few. The law grants the team access to any place of public accommodation. A dog that barks, sniffs others inappropriately, runs around, or otherwise causes unnecessary commotion loses access rights under the ADA.
So, to self-train a dog to service dog level, I would recommend that you work out a formal training method to hone Dottie's scent work. My training, for instance, consisted to two weeks of team-training followed by six months of weekly reporting via a spreadsheet of every alert the dog gives, whether correct or incorrect, as well as the context for that alert. The goal is to get the dog to reliably alert in a wide variety of settings. There is no correct alert percentage number spelled out in the law but 80% is a reasonable goal.
The second piece of service dog work is the public access component. In a professional program the dog is exposed to a wide variety of human environments so that they are socialized to them. Walking through a grocery store without sniffing the food on the shelves is one of the basic skills. Many of the "make-believe" service dogs I meet will bark or growl at my dog when shopping at Costco. Simply buying a service dog vest over the internet does not make a service dog. The title of service dog must be continually earned by action each day. (Dottie would be disqualified if she cannot curb her inappropriate relieving tendency.)
I summary, "service dog" is a legal term defined under the ADA. The handler must have a disability as defined under the Act. (Diabetes qualifies and the ADA list of disabilities is deliberately left open-ended and non-listed disabilities may qualify.) Service dogs may be self-trained. Service dogs must provide a specific disability-mitigating action (hypo- and hyper-glycemia alert qualify). Service dogs must calmly and obediently accompany their handler in a wide variety of places of public accommodation.
Finally. a good service dog is very patient at "settling." The dog must often spend hours calmly waiting for his/her handler as s/he goes though their tasks at school and work.