I've had IgA Kappa Light Chain MGUS for 8 years (70 yo) and my Kappa is about 300 mg/L and Kappa/Lambda is 29. It is still MGUS. There is a 1%/year risk of MGUS progressing to multiple myeloma (MM). A bone marrow biopsy will determine the percentage of precancerous (I prefer deranged) plasma cells, DNA mutations, and marrow health in general. MM is not curable, but with various meds it can be managed and progression slowed for many years.

@karishmananda
Your mom‘s blood analysis is very similar to mine. I have been diagnosed with MGUS based on my blood analysis. I have opted not to have a bone biopsy unless my numbers increase significantly. MGUS is a condition that is non-cancerous. It is a precursor condition to multiple myeloma and some other blood disorders. I hope never to get any of that.
The chances of progression to a blood cancer are very low. One percent per year I will post some information about it in the comments below.
My Kappa free light chains were inching up and a year ago was at 113.8. I started taking turmeric, which I’ll talk a little more about. It is very poorly digested so I take it in curcumin form. It brought my Kappa free light chain down to 88.8 in 6 months. At least that’s what I attribute it to. I did not change my diet or exercise patterns and introduced the curcumin. I’m going to see my hematologist/oncologist on 2 January so we’ll see what he says. He kind of rolled his eyes when I told him I was going to take it. As an empiricist, he wants more data to support the assertion that turmeric can alter the trajectory. I totally agree, but I’m very happy with the results that I have achieved. I’ll let you know if my numbers continue to go down.
So I would not be alarmed by her blood analysis. MGUS is a “watch and wait“ kind of disorder. She should go in for blood analysis on regular basis to make sure that there is no progression. Otherwise, she should live her life and enjoy every day. If the statistics ring true for her, she may never progress to a blood cancer. She will get very good medical attention because they will watch her carefully and MGUS for most people has no symptoms.
You have choices about a bone biopsy. Many have had them. I personally have not by choice. I am in agreement with my oncologist that we can wait. If there are any signs of progression, then we will do the bone biopsy. I get periodic scans of my whole body to look for bone lesions, which would be a telltale sign that the disease has progressed. So far I’ve had none of that. I was diagnosed three years ago.
I hope this is somewhat reassuring to you. It’s good to do some reading about MGUS and and then you are better prepared to talk to her physician when you have appointments.
I am not a physician so he or she may have different ideas about this, but I’m giving you my perspective as a patient.
Try to stay calm in your heart amid the chaos of a new diagnosis.

What did your hematologist/oncologist say the next steps would be?