My just turned 6 yr old still needs help. We turn on the water for her, give her the shampoo in her hand (and the conditioner when it's time for that) and put the soap on the bath puff thing. We check that she has rinsed all the way too. She does the actual washing of her hair and body. After we put her conditioner on she can rinse, turn off the water and towel dry on her own.
My 9 1/2 yr old can do everything herself except for turn the water to the right temp, so once we get the water on she is fine on her own for everything else. She's been doing it completely on her own for about 9 mos now, so since age 8 1/2.
Both my girls learned to tie their shoes completely by age 5. By 6 1/2 they should be able to do this skill. Get her eager to learn by making a reward attached to it. Tell her she can go someplace special or something like that once she learns. Try the bunny ears method as well as the traditional loop around method.
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