It is difficult to know which is more far-fetched: real life, or the movie which inspired it.
She will be sharing the dressing room at Dubai International Stadium with stars of the world game like England’s Danni Wyatt, New Zealander Suzie Bates and Sri Lanka’s Chamari Athapaththu.
Which might be a touch daunting, were she not taking such enviable form into the event. The left-handed batter has been a prolific component of a UAE national side that is on a run of 14 consecutive wins in T20 cricket – the longest ongoing streak in the international game at present. Theertha herself has yet to experience defeat in international cricket.
And all this, despite the fact that she had not even played cricket at all as recently as three years ago.
She took up the sport after watching Kanaa, a Tamil-language movie in which the protagonist tries her hand at cricket to make her father, who is a farmer, proud – and ends up representing India in a World Cup.
“The farmer is very passionate about the sport and his daughter decides to take it up, while her mother is actually very worried about it,” Theertha explained.
“She doesn’t want her to move forward with it. Her dad supports her and eventually her mother gives in, and they go and let her play.”
Which is not exactly like her own home life. Both her mum Rathna, who is an architect, and dad Satish Selanambi, a finance professional, have been fully supportive of her pursuing cricket in the past two years. Even if her dad is the slightly more lenient of them.
“My dad is super proud, and my mum as well,” said Theertha, who is a keen follower of Chennai Super Kings, and Ruturaj Gaikwad’s batting in particular.
“My dad watches all the matches with me. Mum tells me to study a lot, but dad says, ‘Let her watch. Just until the end of this Powerplay. Just until the end of this 20 overs.’
“They are very happy – happier than me, in fact. They didn’t have any words to describe it.”
Theertha, who is a top-order batter and wicketkeeper, said she delayed telling her parents the good news when she first discovered she would be playing alongside the stars at FairBreak Invitational.
“I was speechless,” said Theertha, who turned 18 last month. “I didn’t know what to say. I was stunned, and still am. It is such a big opportunity.
“I only told my parents three weeks later. I didn’t want to tell them anything before it was confirmed. I didn’t want to get their hopes up and then disappoint them later.
“They said, ‘Why didn’t you tell us before? This is such a big thing.’ They were very excited.”
Theertha has been struggling to maintain her own excitement, too. Although she is a latecomer to playing the sport, she has been a fan of the game for far longer.
“Before playing cricket, I loved watching cricket,” she said. “Be it women’s or men’s, I’m always following the game.
“These are people who I have watched playing, and now I am going to share a dressing room with them. To see what their ethics are on the field and off the field, it is super exciting.”
Having had just two training sessions together so far, the players in the new, six-team competition are still getting to know each other.
But Theertha has already impressed her new captain, Bates, who is the veteran of more than 260 international matches for New Zealand.
“When you are a cricketer you want to hear about the stars of the game, no matter where they are from,” Bates said.
“When we first arrived, even though she is just 18 she was introducing herself to everyone. I thought immediately that this kid has something about her.
“I warmed to her personality because she looked like she was having so much fun. She looks really talented. Now she sits at the back of the bus with me and we chat lots.”
Theertha’s Falcons side will feature in the first fixture of the tournament, which gets under way in Dubai Sports City on Wednesday at 8pm.
They will face a Warriors team that includes her fellow UAE opener Esha Oza.