Jade's reaction was ott,way out of order and disproportionate but I think she definitely has a point about Shilpa and the way she acts.
Shilpa is obviously from a society and culture where people respect their elders, and obviously thinks that Jade et al should automatically bow down to her somewhat. A form of control freakery imo.
Couple this with an inferiority complex from Jade, who has probably spent her whole life with people looking down at her because of her social status, and you have a ticking timebomb ready to happen.
I think that Jade also harbours a hidden resentment that Shilpa is somehow responsible for the eviction of her mother. Before then, you often saw Jade actually sticking up for Shilpa and being a lot more compassionate.
As we've seen before, the BB house can create a pressure cooker environment, and tonight Jade looked like someone who has let resentment build and build and build (possibly because her communication skills aren't that good and she doesn't know how to express her frustrations), and then has finally snapped.