A.V.
You have to remember that she did raise her own kids and they turned out alright. Plus if it was your mother asking you wouldn't think twice about letting her go. Your daughter is also going to be around bratty kids and she just needs to know that just because they are that way does not mean she needs to act that way. You can't be around her all the time, your MIL obviously does good watching her when ya'll want her to, so I would give her a chance. Has she ever done anything that you disaprove of and then after you tell her that you don't like it then she does it again? Or has she ever lost your child and not watched your child closely that she got hurt real bad? You have to put all those things into your decision. I wouldn't let my nephew keep me from letting my kids go with their grandparents to have a day of fun. I am pretty sure that your MIL will not let your daughter get lost. If you do decide to let her go then just call and check up on her and remind her that she needs to be on her best behavior and you do not want her acting bad when her cousin acts bad.