Love! It's in the air. What better way to show your love for someone than to get their name tattooed on you, am I right? There's certainly a lot of debate to be had there.
The first time I really remember an artist trying to talk someone out of a name tattoo (decades ago now...), a fella came into the studio I was working at and wanted, 'STEPHANIE' in big block letters entirely across his whole chest. The artist hemmed and hawed, trying to talk the guy down, explaining that a lot of the time, the tattoo will last WAY longer than the relationship.
"But she's my fiancé, and we're getting married in two weeks!" he pleaded irately at the artist's lack of appreciation for the intensity of their love.
Ultimately, the artist gave in and carved in this massive name on the guy's chest. 'Cause it had to be bigger, of course, so she knows exactly how much he truly loves her, right?
Less than two weeks later he returns, tattoo still healing in several places. He was now looking for a cover-up. After showing her the tattoo, it didn't sound like she was as appreciative of his gesture as he had hoped, finding comfort in the arms of another fella. Or who knows, maybe she was screwing around on him the whole time. Was a long time ago and doesn't matter, lolol... That shit didn't work out.
Point is, tattoos DO often last longer than relationships.

I also remember the first kid I turned down for a girlfriend's name tattoo. I say kid, and I was only around 25 at the time, but he was wet behind the ears, even for 18. He wanted her name on a banner over a heart with a dagger through it, the whole nine yards, and it had to go from shoulder to elbow. He emphatically explained how they had been together for 6 whole months, and that he LOVED her! He was upset that I was declining and I tried to explain it to him, hoping that someone in his life would tell him it was a good thing. I figured he'd just go somewhere else to do it, then find out on his own later, but I didn't want to take his money to stick him with that likely outcome.

I realized that I maybe needed to come up with some rules for myself as an artist. Ethically, it's really important for us to consider these things that you come to us with, even if you don't, as tattoos will very often last longer than you will.
I decided that 5 years together and a kid was a pretty good standard, so I started to apply it. A pair of friends of mine who had been together for a little more than 5 years and had a young girl together were anxious to get in and get some matching tattoos. They weren't going for names, but arm bands with an initial for the other person. Not quite as bad as a full name, but an initial can be hard to explain away to your next-in-line. As you may already see coming, about a week or two later, he showed up at my door, looking for a couch to crash on since there were officially no longer a couple.

At this point, I try and share these stories with people as a disclaimer, but if you've been with someone for a really long time and you do share children, you're already bound in existential ways.
I can say this, however. You're really much better off going with an image that reminds you of the person, and not a name or initial. It can be explained away more easily if things don't work out. I've heard some people suggest getting the name or initial in a color, instead of straight black, so that it's easier to cover-up later. I think that tends to not hold up as well and can look odd, so I'd say stick with an image and try to keep it simple and fun.
I've heard some people say that it's a curse to get someone else's name tattooed on you.

Honestly, it seems to me that the people who have come in over the years and had issues after, were trying to compensate for problems that already existed between the two. "See? Look how much I am into this and love you!"
Don't do it as a hail Mary for your relationship, but there's nothing wrong with wanting to celebrate your time together. Although you should make sure that it's not only worth it, but do it in a way that could be more easily 'corrected' down the road.
Good luck this VD! I'm sure you've already got something good picked out, it'll be great. Or maybe not, guess it'll be whatever you make of it, so don't fuck up this year!
Lololunaticleif