I Will Be Visiting Them in June and Will Let Everyone Know How It gGranddaughter

Instead of telling her no redirect her to an acceptable item or activity. You can't play with the TV control but you can play with a toy and hand her the toy. It will take time for her to learn this new way of doing things.

At 3 she still doesn't know how to manage her feelings. When she cries for no apparent reason, give her some extra attention by saying, I can see that you're upset. Will you tell me about it? Accept her feelings while helping her to cope by listening, empathizing, and giving her something to do or play with.

go back to the basics.

HEALTHY Food, she is going to have tons of bad behavior and melt downs if she is eating frenchfries and hoho's all day and never any fruits or veggies.
Same with staying hydrated, she needs water or milk, NEVER SODA.

and she needs 11 hrs of sleep a night. 3 is the age she might be stopping a nap and that can make for a cranky kid too, keep the same bed time and the same wake up time. This will help a TON.

Last thing is attention, she wants her family to talk to her to play with her, to let her help make dinner. please don't park her in front of the tv all day.

Sounds like she's lacking in ways to vocalize her feelings OR she never gets listened to when she tries.
I have a 3 year old granddaughter, just spent 3 days and nights with her, she never cried once, has great verbal skills, tells us what she wants and needs... that really helps a lot.

Your granddaughter is going through the Tyrannical Three's (as is my 3 year old grandson.). She is "ruling" her mom with her crying, manipulating her, basically having a temper tantrum to get her way. As long as she gets her way by crying she has no incentive to stop the behavior. Children need boundaries or limits in their lives, it teaches them what to expect and actually helps them to feel more secure. A "no" isn't the end of the world, though it seems to her it is.

If Mom has a hard time telling her "no" and sticking to it, ask her what will happen when your granddaughter goes to school and is told "no." Schools and teachers don't cater to children and she will be in for a rude awakening.

Whenever she starts to cry she could be sent to her room to cry alone with her door closed, that sometimes stops children from crying since they have no more audience. When she is ready to stop crying and come out of her room your daughter could then teach her how to use her words to express what she is upset about, and encourage her to use her words BEFORE she starts crying over everything. She can also use this time to tell her we don't always get our way. If she is consistent each and every time eventually (and it may seem likes it takes forever) your granddaughter will grow out of this.

I agree that mom should keep on saying no, but consider, does your granddaughter live in a "yes" or "no" environment? What I mean by that is are there all sorts of things within her reach that she should not play with? Is her time somewhat structured so that she does not have the opportunity to think up "naughty" things to do? We had to re-organize the house and lock some doors when my son was younger so that there were fewer temptations/frustrations in his path.

My oldest granddaughter (almost 3) is the same way, it has gotten to the point that my daughter calls me to talk to her and discipline her. Sometimes I try to explain to my daughter that she needs to either let her cry, and not give into her everytime she starts to get frustrated. She needs to stick to her guns!!

One day when she is a real lot older and if she does this, then of course Mom can get help for her. In the meantime she is three and she needs to hear No and in fact oftentimes children want to hear no. They don't know what is safe or right or wrong and they have to be told this word. Many times. They are babies and they think they want their way, but if their way means they should cry so they can do something that seems fun but is unsafe, then well,, they should be told NO over and over again. You probably remember that with your daughter? We want them to grow up safely and securely and with good health and so that means No, again and again.