A grieving mother get prescribed drugs that gives her visions of murders that later occurs.

The logline could use a twist, like she envisions a murder where she is either the perp or the victim -- and must struggle to prevent it. (The former was the twist in the Minority Report)

I forgot to mention, that doesn't mean you don't have a great idea, just that it isn't represented in your logline as written.

Sounds interesting, good luck with this!

The problem with this logline; there's no story, only situation.

If the grieving mother saw a specific murder that she must stop then there would be a story but as written you don't have a story, just the set-up for a story.