I'm going to answer this because it was asked respectfully and not spammed a dozen times like it has been by some other fake Patriots fans from NYC in this thread.
If you think that SI routinely pays sources for information, then sure, maybe she got paid. I don't think they do, most media outlets don't pay for information (except for National Inquirer, etc.) as there are serious ethical violations in doing that and it reduces the level of trust in the outlet:
Chequebook journalism - Wikipedia
Now the counter-argument might be that you hate SI because of Deflategate or whatever, or you hate all news media because of political reasons. That's a different argument that doesn't belong on this board. If you think that all news is fake and just pays off sources then we just have to disagree on that because neither of us is going to convince the other.
If you think that SI doesn't pay sources except for this one case because they are trying to hurt that Patriots then that's yet another discussion and I'd say it's homerism / tinfoil hat (not saying you are, JMC, but others might).
To answer your other (reasonable) question then I thought
@QuantumMechanic had a great post which was that the NFL has the potential to act faster to make it stop than the cops or the courts do, which could take weeks to months. It was actually pretty smart IMO, she knows how these things work.
Everyone on here is saying "The Patriots need to sit down with AB and tell him to stop being a distraction and sending text messages". Going to the NFL makes that happen a lot faster.
Also earlier this week, we talked a lot about your question about why she went to SI in the first place which was just that she heard that AB had assaulted another woman and wanted to go on the record with her own experience to support that woman (which from my perspective is reasonable even if I think the assault charge is questionable).