There is a lot of "think"ing, "wonder"ing and "maybe"s.
I already posted to address the food and the male not contributing to feeding,
Bring the food and water bowl closer to the nest entrance so she can eat and drink easier, as she has no male to feed her or the chicks. Does Pepita eat pellets? You could crush some into powder and make a formula for her and feed it her on a teaspoon.
hatched yesterday at 7pm but has been crying all night
What time is "all night"? If hatched at 7pm, that means those hours going into the night, the chick will be absorbing the yolk sac first before being fed by their mother. By the early hours of the morning, the yolk sac should be absorbed and the chick should have been fed, check the crop to see the contents. If the crop is empty, or almost empty, give the hen 10 minutes or so and then step in and feed the chick.
Return the chick to the nest after the feed and monitor closely for any signs of being rejected (not being brooded, being pecked at). An hour later check crop to see if another feed is needed or if there is still food in the crop or if hen has fed him.
I asked what Pepita eats, if she eats seeds, you will see the difference in the chick and know if the crop contents are remnants from your feed or seed from mum.
That would be something you would need to check in the moment. Sometimes it can take a little time to hatch, but the hen will usually assist.
Lovebirds are not the cry baby / fake cry / attention seeking type. When they cry, there is usually something going on (though when they are a little older, then can sometimes "cry" while falling asleep, cheeping quite loudly.
Be sure you are getting in there and checking the chicks. I found that distracting the hen with some millet spray in her cage would buy me enough time to check in the nest. You could try that, or her fave treat, see how you get on.
Luno (turned out he was a boy ) is a Roseicollis.
Pepita is a Fischeri.
In case I forget to mention it later, these chicks are all infertile. They are hybrids. If you decide to rehome/sell some, it´s important to be honest with the other person and be sure they understand.