My grandmothers twin brother just passed away and they were really close to each other, they felt everything that the other twin did and I am afraid of what I am hearing and my mother has researched that my grandmother can pass away since they were that age and close. Can you please help me with websites with twins that are this age and death cause I don't know what to think right now and I am not ready for another funeral anytime soon, I have lost 4 people I knew and two of them I really loved

For every case it happens, there will be dozens where it does not, It is must more likely to happen between a husband and wife, married for many years when one dies, the other loses will of life.

The real issue of the sister still alive, at 72, how is her health, if she has many health issues, the emotional stress of sisters death will cause more. Is she married, does she have a fulfilling life now, active ?

Merely the death of a close twin, while having a large emotional stress, it is only one issue that can cause additional health problems.

Also longevity has impart some issues of DNA, which the twins share.

Well said by Fr_Chuck.
I'd like to add that you and your mother need to spend as much time as possible being supportive of your grandmother, and not dwelling on what might happen. I'm sorry that you are going through the grief of loss of loved ones. But reading about negative predictions isn't helping at all (unless you want to mope about this and bring her down further than she is). Of course out of millions of twins there are those who die near in time to each other! None of the twins I know have, however, and I am 68, not far from your grandmother's age. And I don't think the statistics bear it out. There might be cases of shared genetic medical conditions of course.
A positive thing you can do is gently encourage her to envision her brother right beside her. I have done that many times with my dad, who died not long ago. I talk to him, tell jokes, ask him what he would do, and even argue with him (he was always sweet and gentle, and I'm not).

How old are you? I think family helps support each other through acceptance of the death of loved ones, and cherishing the memories. Death is hard to accept, young and old, but it's a part of life we help each other live through.

You cannot run from grief, but you don't have to be morbid or fearful of it either.

The death of any loved one causes pain, and heartache. Twins, no matter how close, don't experience more pain because of a loss than anyone else that experiences the loss of a loved one.

Your grandmother is 72. She's still alive, over a decade older than both of my parents when they passed. Instead of focusing on her possible death, focus on her life.

Death is hard, she'll deal with it like everyone else has to deal with it. It's a part of life. Being a twin doesn't make it harder, or easier. It's the same for everyone that loses a loved one.

Just be there for her, listen to her, and spend time with her. Stop worrying about things. Fact is, at 72 she doesn't have a lifetime left to be there for you, so appreciate every moment. In fact, do that for everyone in your life, because you never know when it will be the end.