I think the best advice is to start slowly increasing the amount of time that they are with you. What do you have now-50-50 or something else? If you have less than 50-50, you need to work up to at least that and then try for more. It is unlikely that you will ever be legally awarded more than 50-50. Is she such a bad mother that you think she should only have her children 4 days a month? I try to look at it like this- how would I feel if someone took my children away and told me I could only see them every other weekend...It's not a fair arrangement for anyone. I think the only way to go from sole custody of one to sole custody to the other is:
Death
Agreement of the sole custodian
inprisonment of the sole custodian
outside of one of those circumstances- you're most likely to get 50-50 or less.
Death
Agreement of the sole custodian
inprisonment of the sole custodian
outside of one of those circumstances- you're most likely to get 50-50 or less.