Treatment plan questions following my wife's recent diagnosis?

I'm so glad your wife has you in her corner. I was also hormone positive, HER2 negative. For me, the time between dx and surgery was frightening because I had way more questions/uncertainty than answers. The period between seeing the report in MyChart to meeting with the surgeon was 6 days and I spent most of that time googling (not the best idea:-)) and reading everything I could get my hands on. All things cancer took up most of my head space during that time.
My first meeting was with the surgeon who went through my biopsy report with me and at that time learned my staging. I elected to go with a lumpectomy, followed by radiation and 5 years hormone therapy. I just wanted the cancer out asap and felt comfortable with the surgeon so I scheduled the first available surgery date and elected not to get a second opinion.
My clip was placed the day before surgery to help the surgeon pinpoint the exact location of the tumor. I reported for surgery at 6am and was home by 1pm in a compression bra. She removed the sentinel node during surgery and it was clear so no need to remove addl nodes. I then waited almost a couple of weeks for the pathology report and was relieved and felt very lucky to learn that my margins were clear and the tumor was removed in its entirety.
The surgeon assigned the oncologist she felt best would suit me and I met with the oncologist about 4 weeks post surgery. The onc went through the surgery pathology report with me along with the breast cancer recurrence risk calculator. For ex if I only had the lumpectomy and no radiation and no drug therapy my risk for recurrence would be such and such or if I only had the lumpectomy and radiation but no drug therapy my risk would be this percentage and so on.
My cancer was early stage and along with some other criteria I was a candidate for APBI (abbreviated partial breast irradiation) which is a course of radiation 1x/day for 5 days. I know there's all sorts of opinions on this but the research is there and I felt more than comfortable with this decision. I had some fatigue but overall minimal side effects for which I felt very fortunate. I was proactive with keeping my schedule very light that week, staying well hydrated, using calendula cream on the treated area, etc...generally just being kind to myself:-)
Approx 6 weeks post radiation my drug therapy started. I've been lucky in that my side effects haven't been so bad but I know that's different for everyone. Your wife's oncologist is the one to help navigate that.
It's been 18 mo since my surgery and I meet with my breast surgeon every 6 months for a breast exam and check in. I also meet with the oncologist for follow up and check in but as long as everything continues to go smoothly I'll meet with them one more time and then I'll be on a yearly appt basis.
Cancer turned my life upside down and it was all I thought about for a long period of time. It's still in the back of my mind but thanks to the support of my husband and the friends/family I chose to share with along with my breast oncology surgeon, radiation oncologist and oncologist (my team!) I'm doing really well.
Nobody chooses this journey but this forum is a wealth of information and beyond helpful - you and your wife are not alone.