Do you think I have Lyme if...?

My sister hasn't been feeling to good lately, she most of her glands are swollen, she has joint pains, no appetite, sleepy, and a low grade fever... The doctor thought it was mono, but it came back negative... My dog sleeps in her bed during the day sometime and she had a tick on her this morning... Also my sister had pulled a tick out of her scalp a couple months ago... If you could please answer if you think it is Lyme or not that would be awesome, just to ease my mind! Thanks