You know the saying: There's lies, damm lies and statistics.
That's the problem Ripsnort, you can use statistics to bolster any argument.
More Blacks are killed by guns could mean any number of things. Whites could be killing them, easy availability of guns could be the reason, Blacks are naturally more violent, more Blacks are poor and poverty leads to crime etc etc.
Let's see if I can read both your minds, she is against guns and the facts are there, that the easier availability of guns in the US leads to more gun deaths. That is a 'fact' you don't like and disagree with. You are in favour of guns and point out the 'fact' that most gun deaths are among Black males. The implication, whether you believe it or not, is that Black males are more prone to gun violence. Thus guns are not the problem but Black males are.
In fact it's more likely that males between a certain age living in reduced circumstances and in a high crime environment may be more prone to gun violence no matter what the colour. Now it is quite possible that in fact it is true to say that Black males are more prone to gun violence than white males. But because of historical racism this isn't a popular option.
To sum up both your arguments, whether real or implied. She thinks the American gun culture leads to excessive gun deaths. You believe it's a Black culture thing. You may both be right but the nature of debate is that we do not agree with each other all the time and we all have our own biases and prejudices.