For the perhaps hundreds of "psycho something" movies on Lifetime - and having shamelessly admittedly watched darn near most of them, I will say this is one of the better ones.
Former fashion model turned-actress Brooke Burns portrays Suzanne the vengeful sister, and she does all the things we come to expect from a Lifetime movie psycho trying to wreak havoc on a mostly doting husband - fake or contrive an affair, infiltrate the household, plant suspicions in the marriage, ruin the husband's business, and otherwise ruin his reputation in the community.
I'm actually truly saddened that Michael, the husband victim, simply allowed the abuse and manipulation go on and on and on, just simply hoping magically that it would all just go away by itself. We all know the psycho cavalierly simply continues her psycho-ness until she gets shot or hit over the head with a shovel.
And, of course, when he tells his wife or best friend that he's "going to put an end to all of this" that simply means he's going to vehemently confront the woman very publicly - almost always, making matters yet worse, resulting in a restraining order. If he had watched enough Lifetime movies, he would know quite adroitly that that NEVER EVER works.
It also annoyed me that Michael never ever tried to go on the offensive, cause some disruption in HER life or set a trap... something! No. Instead he simply allows things to escalate to the point that his wife is physically harmed MULTIPLE TIMES and his recent-born baby is put at risk, and he's on the hook for ATTEMPTED MURDER. AND STILL he was willing to simply comply the psycho's demands.
Despite these annoyances, this was still a pretty decent psycho movie in this genre which is why I gave it a single notch above average.