You definitely want to talk to the boyfriend, with a baseball bat. Tell her to find a new one who wants to actually work and support a family. Don't be afraid to voice your opinion.
If you voice your opinion, but the other person is not even listening, then you will not get anywhere, all they will hear is "I don't believe in you" or "you're not grown up enough to decide for yourself", and that's just going to trigger allergic reaction. To the contrary, I'd try to help, and together start to look for a professional who can help develop a business plan and sort out the logistics, and whom SHE could consider credible and unbiased. I'd let her take the lead in the process. Maybe this entrepreneurial experience is what she's looking for? Eventually, either she will turn out to be a natural, or more likely, before moving to Puerto Rico, and getting too committed, she may realize this is way over her head, and that she depends on the parents for money and guidance. I'd think that the ability to help in realizing (some of) her dreams is one thing that a parent has to offer, and a major source of influence in this negotiation, and that's not strictly about money, but she will have to understand that first...