Baby wood Pigeon PLEASE HELP

Today is Sat 16th July, 4 days ago I noticed 2 baby wood pigeons in the large apple tree at the bottom of my garden. Today I can only see 1 so I'm guessing 1 has taken flight.
On the 1st day the parents came back and forth and appeared to feed them. After which they returned to check on them while graduating their distance. I believe I saw 1 of the parents early this morning spending some time close by. The parent did fly into the tree, so maybe this was to feed it. I'm not sure.

I'm very concerned, I've had baby pigeons and baby magpies in the apple tree before, but they've always taken flight within several days.
As mentioned it's been 4 days and as far as I can tell The baby appears alert and I've noticed it nibbling on leaves etc so I'm assuming it's eating insects and therefore getting some fluid this way.

The tree provides plenty of shade and there's many food and water stations available close to apple the tree, however, my concern is that the next few days are forecasted to be record high temperature.

Is there anyone that can give me some advice, I feel like a 'Mother hen'!
Does anyone know if its usual for these birds to spend 4 days or longer before taking flight?
Is there anything I could do or should I just leave well alone?
Any advice is appreciated

I know nature will deal with things its self, I just look at this funny looking bird with it's over-sized beak for its body and I'm overwhelmed not knowing if there is anything I could do to help, taking into consideration all the damage we've cause mother nature.
That said I really don't want to make things worse.

Eagerly awaiting any advice

Many thanks
Rachel