Welcome to Connect, @tperez3333 I’m so sorry to hear your daughter has leukemia. As a mom it’s not an easy thing to witness, seeing your daughter facing chemo and the challenges of cancer. I went through my own ordeal with leukemia 5 years ago and empathize with you and your family.
Unfortunately bone marrow biopsies and aspirates are an integral part of the diagnosis and treatment process of leukemia. Getting analysis of a core sample of marrow and the aspirate of liquid in the bone marrow can give the doctor a clearer picture of how well treatment is working, how well the marrow is functioning in being able to make healthy blood products, level of disease, etc.. On occasion, there can be ‘failures’ or I think they’re called dry taps where not enough of a sample of aspirate is gathered to analyze. From my understanding, sometimes there needs to be a repeat. I’m wondering if this is what you mean?

What type of leukemia does your daughter have? Is she being recommended for a bone marrow transplant?

@tperez3333, I'd like to add my welcome. It can be hard to know what questions to ask when you don't know what you don't know. Remember, no question is a dumb question.

I would start by asking your daughter's cancer team questions like:
- Why were you not able to get a successful sample during the bone marrow biopsy?
- What can be done to ensure success at the next biopsy?
- Is there an alternative that can be used if biopsy is not possible?
- What are the next steps?
- What else do I need to know?

Has your daughter had the second biopsy since you posted? How is she doing? How are you doing?