Is spinal tap necessary to diagnose Lyme?

[Tina0468]

My daughter, who is 6, was bitten by a tick about 6 weeks ago.  My husband removed the tick, in its entirety, with tweezers, and I took her to her pediatrician the next day.  My daughter had said she didn't feel well and was running a low grade temp that morning (the next day after tick was removed).  We brought the tick in to the dr. and they looked at it but gave it back to us.  The NP wasn't too concerned with the possibilty of Lyme, but prescribed antibiotics just in case since she wasn't feeling well.  The NP gave me a liquid antibiotic, which I forgot to start right away.  She ended up getting about half of the dose (it was prescribed for 7 days.)  I believe the tick could have been on her for a couple of days before it was found, so not really sure the exact time lapse since the bite.  I've noticed that on the left side of her neck, the same side as where the tick was found in her hairline, she has two small lumps which I believe to be swollen lymph glands.  This is the only symptom that she could possibly have of the Lyme that I'm aware of.  She never did develop the typical "bullseye" rash, has not complained with having sore muscles or joints, no headaches, no chest pain, etc.  I plan to call her pediatrician tomorrow to ask about her lymph nodes.  My question is, is that when I was in the office with her previously, the NP told me that to determine if she had Lyme, should she develop symptoms, is to do a spinal tap.  But on the internet I've read about the blood tests that can show the presence of Lyme.  I REALLY do not wish for her to go through a lumbar puncture, especially since she is NOT showing neurological symptoms.  Is there something specific I should ask for (or avoid) as far as testing goes?  

Thank you for your time, Tina