Is it too late to send a thank you?

I had an interview on Tuesday. Today is Friday. Is it too late to send a thank you to the nurse manager. I did not realize that you are supposed to send a thank you within 24 hours of the interview
I have had a total of three interviews for this position. The first was a brief phone interview with the nurse recruiter to discuss my experience and interests. I applied for several positions. The second was Tuesday 1/12 with the NM and and assistant head nurse. They seemed very interested. The NM stated that there were 5 applicants being considered. I was the first interview. She said she would probably interview one more and that's it. I REALLY want this job!! I had my 3rd interview today by phone with the nurse recruiter- she had to reschedule last minute after I already arrived yesterday. I plan to send a thank you to her today. Sooo, would it be lame to send a thank you now to the NM? It's been 3 days since the interview. Is it too late? Could this cost me the job?