I have two Mira bags - smooth leather in Grey Blue, and the quilted in black with black hardware. Relevant to your discussion, I also have the Cassie 19 in Petunia with the same heart link leather strap as the Mira you're considering.
I love my Miras, the style sits so nicely against my hip crossbody, and it's the perfect size for me. I also love my Cassie 19, but for me, the heart strap is too short and too lumpy/uncomfortable to wear on the shoulder - I use it as a decoration on the bag only. I let it hang down while carrying it crossbody, and I also have some silver strap extenders that I use with the leather shoulder strap and that works well with the heart chain hanging down as well.
For the record, I'm also over 50, and give zero you know what's if anyone thinks something is "too young" for me or otherwise unfashionable.