The death of Kathy Stabler left a huge mark on Elliot Stabler and it's one of the main reasons why the Organized Crime unit exists. Her death gave Stabler PTSD and set him on a path of revenge, but some fans are starting to wonder if her death was actually as final as it seemed.
The last we saw of Kathy was in Season 1 of SVU when she suffered from a cardiac arrest and died. She had been married to Stabler for a long time and they had five kids together, so she was a big part of their lives.
When she died, she had just learned that her oldest son was leaving to join the Marines and she wanted to spend as much time with him as possible before he left. At the time, she was also worried that Stabler would continue to focus on his work and not spend enough time with the family.
Throughout the show, we see Stabler struggle with his personal life more than once, and he isn't always a very present dad. He has a hard time opening up to people and often chooses Olivia over his family. However, he does try to do better in season 9 and begins to open up to police psychiatrist Dr. Hendrix, who helps him work through his issues.
It looks like that's all about to change again, though. As we've seen in the trailer for the next season, it appears that Stabler and Olivia are about to have a baby and this will be their first child together.