I saw this too. I might be wrong but my take on her comment and her tears were that she is a good person with a kind heart.
She has dealt over the last year and half with the loss of Haleigh, and now, the Father of her remaining child is going to prison for 15 years. A lot for not only her but Jr to deal with.
He was a inadequate Father to both children. I would imagine she aknowledges that, just as many of us also have raised children that had Fathers that were inadequate and completely remiss in their responsiblities as a Father.(although not many of us have children with Father's who had the another of our children last and now that child is gone)
I've seen video (lot's of video IIRC) where Crystal cried for Haleigh. Now, not only is her daughter gone, but the reality is that that same Father will be in prison for almost all of Jr.'s childhood.
We can dislike the Father of our children very much sometimes, but the fact always remains, and it's a fact we can't change that that is our children's Father.
Would I have reacted differently? More than likely I would have, but I'm not Crystal and I view her response as a healthy one on behalf of her remaining son. She to me is acknowledging the profound impact this will have on him. This poor lil' guys life was irrevocably changed the night Haleigh died. It just seems to get worse for him. Now do I think that RC should have had unfettered access to Jr? Nope, and even if he is eventually convicted of harming Haleigh, that will never change the fact for Jr. that RC is his bio Father.
Her response to me, personally, shows me a depth of character and a kind heart, and tells me that she truly loves her Son. But I really don't think this is about RC JMHO.
All Just my take on it, but I don't follow as closely as you all do. JMHO.