I'm 65, and will be receiving mammary feminization (yes, that is what the provider is calling it!), or Breast Augmentation (BA) in a couple of months.  I'm a small 34B, and will be adding an estimated 275-300 cc in each side, under muscle.  The surgeon will determine what size works best.
I fully expect to have this 'unnatural' tight appearance for a while as things settle down and tissue swelling slowly goes down.  I am OK with this.  
I expect to look 'unnatural' for my age afterward, as unlike many cisgender women my age, I do not expect the twins to be swaying down at my beltline.  I am also OK with this.  I am quite certain my girlfriend is OK with this.  

The goal is to feel right, feel comfortable in my body, to be able to dress as I want to dress, to don a swimsuit and be stared at for all the right reasons.
Yeah, eventually I will be the most rock-solid looking woman in the memory care unit.  I'm OK with that, too.  Eventually.  Meanwhile I get to be me, whole and complete.