Breaking a Parents Bad Habits

Well I never did get the chance to buy new pillows. I am just too tired and unmotivated to do ANYTHING lately. I currently babysit for 4 kids age 1-8 plus my own 2 who are almost 8 and 11. I only started watching the 1 year old and 8 year old the beginning of this year. The 1 year old is a challenge and the 8 year old brother can test my patience. I must have forgotten the days of whining and crying because I don't remember my kids acting like this. The one year old cries when I leave her sight. She is adorable and very loving. Always walking up to me for a hug, a kiss or just to snuggle. She even tackles the other kids for hugs. When she is dropped off and picked up she seems like she never wants to leave. Naptime has been very challenging lately. She will not go into the crib and alot of times I either have to hold her or lay next to her until she falls asleep. Nap time is my saving grace. That is when I TRY to get things done around the house, check emails or make phone calls. Turns out her parents let her sleep in their bed so they can rest but she still gets up 3-4x a night. HOW CAN I BREAK THIS HABIT?? Did I also mention she barely eats and only wants Gerber puffs? If she doesnt get her way, she screams and cries louder. I can't even go to the bathroom or answer the door without her or there will be loud crying with snot and crocodile tears for at least 20 minutes....ANyone have a suggestion or advice to offer. This might be the child that will be my breaking point. HEEEELLLLLLPPPPPPPPP