If you die in the same car accident what happens then? As she is younger and you both die at the scene, she would get it then it passes on to her next of kin. But if you outlive her and cark it on the way to the hospital, her half passes to you, and from you it passes to who? The state? Your next of kin?
Would it be better off going to her nephew say, than your parents? Theoretical I know but the will puts these things on paper. If you are happy your assets going to people you might not like as they are her next of kin, or indeed she is happy with her assets ending up with yours, or both of you are happy the state gets it all. Then no there is no need to a will.
On the other hand Death Scenario mapping is fun, so don’t shy away from it. Bring a 10 year old boy if you want to map out all bizarre scenarios, I can rent you one. But it’s good to know that in the even of a minibus based death with all the family, some dying, some on long term life support, some transferred to robots, others in suspended animation. It’s all mapped out, so not to worry. You might not need to go to the same level…