Raavi is certainly an interesting character indeed!
Personally speaking, I think the reasons she hasn't shown any resentment to Dev can be three-fold (with the third reason being the least likely in my opinion):
1. She considered Dev to essentially be dead when he left her at the mandap for Rishita. Dev is her childhood crush for 10 years. She's always thought of him to be some sort of perfect soul because he was there to "pick up the pieces" that Shiva dropped. She was so used to Shiva hurting her and Dev protecting her, that when Dev hurt her for the first time, she considered him and her childhood crush to essentially be dead. In psychology, you could consider that she has "dissociated (i.e., completely removed)" her memories of Dev with actual Dev. As such, it probably is difficult to be mad at a person who is quite honestly dead in your mind.
2. Dev is now "older" in terms of relations to her. As the elder, she cannot truly "hate" him or insult him. Therefore, she is showing both hatred and her blow-outs to Shiva who is an "equal" to her. It is a little sickening to see Shiva get the brunt of her anger, especially since he does not deserve all of it. Some it maybe. But not all. But, I think part of the reason may be this. Or maybe the makers want to explore this concept further in the show. So far, Dev and Raavi have not had a scene where they are alone, so this might be the barrier, but even so, she hasn't even shown a cold shoulder to Dev...
3. This is my least probably (but still wanted to include it nonetheless) thoughts, but maybe Raavi doesn't want to put any sort of hatred towards Dev because in her mind Dev is "perfect" and she wants to preserve that perfect image of him. As such, she hurls all her hatred and insults to Shiva while sparing Dev everything.
Hatred is truly something that is heavily explored in history. You can never explain hatred, that's for sure, and if left unchecked, it can explode to something as dangerous as a war. In Raavi's case, it's interesting, because misunderstanding after misunderstanding, nothing seems to be getting resolved. It's all the same. It's her criticizing Shiva and Shiva running from there without answering her. I think the running away is what is causing her hatred to build up...