I know it's a little farfetched and I do have all the time in the world to think it over but what'd you think about angel wings as a tattoo?
They can be easily hidden so that isn't a problem...
Just something along them lines:
You were the angel of my life, taught me to be free
They'll also take several sessions to complete. My shoulder piece isn't nearly that big and took two hours and my artist still has to go over it once more. If you really want them for a meaningful reason, and have thought deeply about it, go for it.
The artist has other appointments
Tattoos like that can cause trauma (muscle twitching etc.)
I suggest you do a lot of research. My tattoo just has a lot of coloring in it, yours is more of an outline.
Still, because of the size and location on the back it could take a few sessions. It's also crazy expensive.
Why does it take several sessions? I can see why it would take several hours to but why would you need to go over it?
Also, during the healing time, the ink may be pulled out and especially due to the placing it may get irritated by clothes etc.
This may cause it to become patchy.
It's no big deal though, it happens to most tattoos, including mine, and the artist just goes over where needed.