If you can still have the OncotypeDX genomic test done, you can have an idea of your risk of recurrence. And, if it's very low, it makes decisions easier as a low score also suggests against chemo. I had the test done nearly 3 weeks after a lumpectomy so the time lag wasn't an issue.
(And the resulting low score was helpful.)

I was offered local site-specific precision radiation that was every other day for a total of 5 sessions. I think it's considered very low risk but is specifically to "clean up" the area around the tumor site and offered only that local protection in case some rogue cells remained. I didn't have it but think it's not a bad idea. And if the tumor (caught at stage 1A) were larger or the sentinel node biopsy detected cancer cells, I likely would have had it. But I hope you get enough information to look at the options and don't rule out anything just because of age either. Just look at the big picture and which decisions would 'wear well' meaning least likely to cause second-guessing later.