I'd just ask them what their source of tuna is...if it's canned, I might stay away from it, but that's just me. I do know that fish in general is fine to have about twice a week (to be on the safe side). It has a lot of good benefits too. Frankly I'm surprised you could stomach that right now. :)
I'm a pretty firm believer in cravings meaning something during pregnancy. If you're craving a tuna wrap, I'd say have it. There isn't much that food you have to avoid.
The biggies are:
- lunch meats (spoil very quickly and produce a nasty bacteria called lysteria) - these are fine if you heat the meat to steaming; that temperature kills lysteria.
- soft cheeses (both salmonella and e-coli can grow in soft cheeses - 99% of the time they are probably fine to eat, but I found it no big deal to abstain from brie, blue cheese, queso blanco, and feta for 9 months)
- raw sprouts (again salmonella and e-coli risk)
- sushi or undercooked meat or fish (same as above)
- unpasteurized dairy products - you're probably not running into any of that unless you live on a farm in France or something
People have also eaten all of the above during pregnancy and gone on to have healthy babies. For me, this is the list my ob and I discussed, and the research that I've done on my own definitely confirmed to me that eating anything on the list above wasn't worth the risk of harming my baby. There are so many other healthy foods out there to enjoy. Congrats!