Sara Trost, 40, died from multiple gun shot wounds last Thursday as she waited outside a house in Coral Springs, Florida.
Married with a three-year-old daughter, Ms Trost ran her own property business.
She was also a motivational speaker and a long-time volunteer at a local animal rescue centre.
Ana Y Lopez, co-founder of Floridabased Paw Patrol Animal Rescue, said Ms Trost had been volunteering and fostering with the charity since 2017 She said: “Sara was one of our most trusted, knowledgeable and beloved fosterers.
“We are still in complete and utter shock about this senseless tragedy.Thinking about her husband and baby makes me absolutely heartsick. We truly cannot come to grips with what has happened.
“It may sound trite, but Sara will truly be missed. She was kind, vivacious, sweet, caring, helpful, giving, selfless I could truly go on.
“I pray for her family, that they may be able to find some peace some day.
“I know they say, ‘Everything happens for a reason’, but this makes no sense at all.”
Ms Trost, originally from Southend, Essex, is believed to have been shot dead by an aggrieved former tenant at the Coral Springs property.
He reportedly mistook her for his former landlady.
It is thought Ms Trost was there to show a potential new renter around the home.
Two hours after the shooting police arrested Raymond Reese, 51, at West Palm Beach, around 45 miles north of where the killing took place.
Reese, of Boca Raton, Florida, was charged with first degree murder and was due to appear in court yesterday.
Ms Trost, an outspoken critic of American gun culture, lived with her husband Jason and daughter Avery in Parkland, a short distance from where she was killed.
Rabbi Shuey Biston, a close friend, said: “We are all devastated. Sara was so loving and caring.
“She was just a really special person.”