Dont retreat, reload.
"Pull that knife out of your back - and sever the fuel line to that bus you got thrown under" Bufffalo
A guy who did work on our house had his wife's name on his wedding band finger. Four letters, simple font. It was slightly faded but I'm not sure how long he's had it.
I was considering getting my H's name tattooed on mine but I can't see it working. 6 letters, small finger...maybe I'll do his initials one day.
Sorry I'm no help. I just want to say---Awesome idea!
Also, you didn't mention how many kids, but I would think more than one 4 letter name would be impossible. Tattoos cannot be that small and have any detail whatsoever, and as mentioned above, they bleed.
For all the reasons stated above, tats on fingers will fade really fast, as well as spread out and blur. The skin on your fingers is very thin, is used and exposed a lot, and regenerates quickly.
Also, any words need to be well placed and spaced so that you won't lose the lettering quickly over time. My father has had our names tattoed on his arms in a few places over the last forty years, and only we know where they are now. I love that he did it, more than once, but it didn't last very long on his sailor's weathered arms.