The Pumaman

It's tiny. Every soccer Mom in the world has a tattoo now. Just get it or don't. But that tiny tattoo isn't going to affect anything. Wear a bracelet, and you are golden.

Maybe she should just use a Sharpe. That will fade quickly and there is no long term commitment.
My advice is to wait until you and your friend are ready to commit to a tattoo. Otherwise you're going to wind up with a squiggly line on your arm, in a very visible spot, wondering what the hell you were thinking. 
You know that you don't just go in and laser them off like on TV, right? It's painful, expensive, multiple sessions and will likely leave something you can still see on the skin.

You're probably not going to get a specific appointment for something so small. Inking time will be less than 1 minute. Total time in front of the tattooist will probably be less than 10 minutes. Be prepared to pay a shop minimum (which will vary depending on which shop in Boston, but probably $75-100). 
I'm not familiar with the shops there, but the pitfall is that it takes almost nothing to screw up very simple design like this, so you don't want to end up in the hands of some newbie apprentice or an experienced person who isn't really invested or interested in helping you out. It's going to be a balancing act. 
2nd on @Dan's comment regarding the white ink choice