"I am delighted to be in the privileged position to be able to award these professional contracts to a group of players who have demonstrated professional characteristics and attitudes in every way but contract status this winter," Carty said. "With a massive summer ahead that will see more matches, a greater competitive challenge from an ever-improving opposition pool and, no doubt, a fluctuation in player availability, we will need a deep and meaningful squad to remain at the forefront of the elite domestic scene."
Monaghan and Taylor have been part of the Southern Vipers' set-up since it became a regional hub in 2020 as part of a pivotal restructure of the domestic women's game, having risen through the ranks at Hampshire.
Taylor, who was just five matches into her career when she made her presence felt in that 2020 RHFT final while also working in customer service for an aerospace company supplying parts for helicopters, said her new professional contract would allow her to focus solely on her sporting career this season.
"I am delighted to have been awarded a contract with the Vipers," Taylor said. "It means I can focus fully on my cricket for the summer and not have to juggle a full-time job for the first time. I cannot wait for the season to arrive and hopefully I can contribute to some silverware this year."
Monaghan and leg-spinner Harman have represented London Spirit in The Hundred, playing under the captaincy of Vipers team-mate Dean. Monaghan said: "I'm so excited to be given this opportunity. This will allow me to elevate my game to the next level, and I can put in some performances to contribute to the Vipers having another successful season."
Hill, who also captains Worcestershire, spent the 2022 season on loan to the Vipers from Central Sparks before making a permanent move at the end of the year having scored 111 runs in five innings for the Vipers with a best of 55, while Southby joined from South East Stars in November last year.
Vipers, who also defeated Northern Diamonds in the 2021 RHFT final before losing to the same opposition by just two runs in last year's title decider, begin their 2023 season when they host Sunrisers at The Ageas Bowl on April 22. Sunrisers are yet to win a match in the RHFT and have won just one of their fixtures in the Charlotte Edwards Cup, in which Vipers are the defending champions.