I hate how the media exploits this. I'm not a fan of the DR, but I don't think it's that "dangerous." Keep the deaths in perspective. There are definitely resorts I'd avoid...like the one that so badly handled the woman who was attacked. But, not the entire country.
Mexico's danger is similarly misrepresented. If you are involved in a drug cartel, heck yes, Mexico is very dangerous. If you go there and don't go to buy or trade in drugs, Rivieria Maya is as safe (or safer) than most American cities in terms of likelihood of being randomly murdered. I love Mexico, and I won't let some people's demonization of the entire country and people dissuade me from going.
As for OP's daughter, there's no way to manage her "feelings." If she feel she can't enjoy the trip, then go somewhere else. Life is too short to waste any vacation dollars or time.
And, just to show how distorted our views are on which countries are "safe", according to the UN, the intentional homicide rate in the Bahamas (listed above as an alternate destination for OP's daughter) was 28.40 per 100,000 residents and the DR was 15.18 per 100,000 residents, Puerto Rico 18.51, the US as a whole 5.31. However, we all know that danger can vary by location within the US. (High of 12.4 as a state average in Louisiana to low of 1.3 in North Dakota). In particular, if you are concerned about being murdered, best to avoid New Orleans (38 per 100,000), St. Louis (66.07), Memphis (27.73), etc.. I do know people here who talk openly about visiting those cities, and they seem to do so without fear of being murdered.