Ayash, mother of three and grandmother of two, drowned while tubing in the after her raft overturned.
The Foreign Ministry is working with the embassy in Guatemala to facilitate the return of the body as soon as possible.
Liran Eldar, one of the trip participants, told Ynet, "It isn't an extreme trip. It's like tubing in the Jordan River in the summer. Staff handled it quickly, but we are all still in shock."
According to Eldar, the group arrived in Guatemala on Saturday and on Monday morning began hiking until they arrived at the Cahabón River. "There is a permanent attraction there, nothing extreme, nothing crazy, just simple tubing. We split into two groups, with each tube being tied to the others; I was in the second group. When we reached the end, suddenly we noticed the other group had split in two and someone flipped over."
Eldar said that medical and rescue services "arrived almost immediately. They managed to make contact with an ambulance quickly and from what I saw, everything seemed to be going well."
"We got to know her well and there was a wonderful group dynamic and a great atmosphere. She was very lovely and very positive," she added.
The company sponsoring the trip added, "We share in the family's deep sorrow. At this time, the case is being investigated locally and the rest of the group will return to Israel as soon as possible."