Looking for a specific type of romance plot (childhood friends to enemies/rivals to lovers)

try:

• Love is Sweet - childhood neighbors
• Game Sanaeha - childhood playmates/family friends
• Skate into Love - leads are childhood classmates, they were too young to 'like' one another but the girl sought to be  the ML's protector which the ML ends up hating her
• Let's Eat (Season 2) -leads are childhood classmates/neighbor, and again they were probably were to young for the 'liking' part, but he ends up saying something that she greatly resented/hated
• Kinda somewhat in the same domain of knowing each other before adulthood/young adults
  • Hello Again - high school classmates,
  • Pinocchio - became rivals in work
  • Neung Nai Suang - childhood playmates but he always bullied her
  • Forever Love - meet each other as highschool students and became classmates, have a misunderstanding and she ends up hating him while he tries to make amends and explain himself
  • Twenty Again

I’m sure there are more, but these are the ones I can think of off the top of my head:

Missing You ~ they were childhood first loves that were separated due to an extremely traumatic incident forced kidnapping and sexual assault, although the latter isn’t graphic it’s definitely present so please be aware, depending on age it might not be an appropriate rec and she hates him while he obsessively searches for her & they meet in adulthood & work their way back to love.

Reply 1997 ~ again, childhood first loves that are separated because she dates male lead’s older brother, not realizing her love for male lead & he gives up on her and he never wants to see her again until they meet (ofc) and fall in love all over again. Or, honestly, they were in love the whole time, just apart.

Le Coup de Foudre ~ they don’t know each other in childhood but are high school first loves, the way they separate leads male lead to dislike female lead & be apprehensive about letting her back in his life. Leads are married irl (idk this always sympathises a drama for me so it might for you & her too)

My Sunshine ~ not childhood but college first loves, their separation again leads male lead to hate female lead. 

Tree of Heaven ~ high school first loves that are technically step siblings (that didn’t grow up together etc) so taboo feelings lead to separation/a mix of love & hate then reunion.

Delightful Girl Choon Hyang ~ this is one of my fav dramas so I rec it often but it might only partially fulfill your request, they’re married at a very young age in high school because of circumstances and then separated as they both realize they’ve fallen in love around college age. Male lead misunderstands why female lead left him and disappeared so there’s a mix of love and hate, but not really, just love and confusion and love again. 

Save the Last Dance for Me ~ this one, again, only partially fulfills your request because they’re around college-age first loves that are separated due to amnesia after early marriage. Reunion brings love from female lead and hate and confusion from male lead since he doesn’t remember her & misunderstands her intentions. 

There are tons more where childhood loves are separated for whatever reason but there is no hate/enemy aspect to them (usually sadness like Autumn in my Heart or Summer Scent or amnesia/fake death of some sort like The Moon that Embraces the Sun). The hatred/enemy aspect of all of these is subject to debate except for in Missing You where it’s definitely there. 

The Bridal Mask  - exact and classic - childhood love, meet as adults and are real enemies, fall in love again..

My Strange Hero dating in high school, misunderstanding, meet as adults, enemies, fall again

Uncontrollably Fond - complicated relationship in high school, ML did wrong her, meet as adults when ML is famous celebrity but with terminal illness, also on off complicated relationship, but fall in love again. 

It's Okay to Not Be Okay - childhood love, then boy doesn't like/is angry, girl likes. and one of best romantic dramas, very beautiful, great acting, cinematography and production value.
Thirty But Seventeen ML loved her in childhood, then FL gets in accident and is in coma for 13 years, meet again, not knowing each other, ML is cold introvert but slowly they fall in love, also this is one of most positive vibe dramas I've seen, with amazing original interesting side characters. 

also, because you like crime genre, and also it's very very good drama, Cruel City, you could watch it with daughter, it's not exactly what you wrote, but  there is one line with childhood sweethearts become enemies (criminal-cop) and then other line also met in childhood - enemies - fall in love. this drama isn't focused on romance but has very good one, also it has another very good plot lines, acting and overall great drama.
also for you both Kill It childhood love - then one is contract killer another detective. really good drama.

Pinocchio - exactly what you described. 2 characters that meet as children and grow up together, become rivals but the heart wins.

Its a really good drama. Highly recommend it. 

The only one that comes to my mind is Dance of the Sky Empire but that doesn´t fit perfectly because they are not really childhood friends, but they know each other from their childhood years,  And they are actually enemies from the beginning, but only the FL knows it while the ML falls in love with her. Then he learns the truth and they become enemies and fight each other but eventually get together.