Bike to bike communication? What options?

[BlumminNora]

My children are now at an age where they would both manage a decent bike ride.
I’m a single mum so I’m looking at a way to be able to communicate with at least dd1 who would be at the front whilst we’re cycling so I can tell her to slow down, stop, turn left etc.
Are there any affordable, reliable earpiece/helmet speakers/microphones.
Apologies if this is a daft question. A good google just left me confused confused

my friend goes out on bikerides a lot with her dc, and she has attached one of these onto hers and her daughters bike. they both wear the headphones that come attached and so can talk to each other easily

all the best