Yes dogs can have strokes, but it is rare. If she's showing no other signs/symptoms then I wouldn't be too concerned about a stroke.. Other symptoms are head tilt, turning the wrong way when called, lethargy, vision and balance problems, incontinence, and more..
Does she have any underlying conditions that you know of? ie kidney or heart disease, diabetes, thyroid issues, recent head trauma, high blood pressure all increase risk of strokes.
I would be more concerned about Lymes disease.. I have seen a couple of dogs with Bell's Palsey associated with Lymes disease. Bell's Palsey happens when inflamation in the facial nerves causes misfiring and paralyze half the face, and the patient is unable to blink or move one side of the face very much. It lasts indefinately. I myself had Bell's Palsey 8 years ago when I first had Lymes, it lasted a month after I was treated for it.
I would keep an eye(no pun intended) on her and take her in to get checked out as soon as you get a chance. If it is Lymes you don't want to wait too long to treat her- some dogs never show any other signs, but the disease can wreak havoc on their bodies if untreated. Likewise, if it is a stroke she needs to be seen anyway to rule out any underlying conditions which may have caused it.
Hope this helps, and let me know what the diagnosis is!