If my kids and I lived with my mother for half the year and she claimed all 3 of us for half the year, do I still put my kids as living with me the whole year?

Are you a full time student under age 24, or a non-student under the age of 19?  

And was it more or less than half the year?  This is important and it matters to the day.  2019 had 365 days so more than half would be 183 or more days.  

You and Mom need to get on the same page, so to speak.  There is no such thing as claiming dependents for half the year.  If she put all of you down as her dependents you have all been claimed for 2019--period.  You cannot claim yourself or the kids for the other half of the year.  It just does not work that way.  If/when you try to claim the three of you, your return will be rejected.  The IRS does not give the child-related credits to your mom and to you.  

You say your mother claimed you----did you earn more or less than $4200 in 2019?  Were you a full-time student?  How old were you at the end of 2019?  We need some details.

if she claimed it's for the whole year.

first you are her qualifying child and thus her dependent if these tests are met

1) as of 12/31/2019 you're uner 19 or under 24 if a full time student

2) you lived in the same residence as her for 183 nights or more

3) you didn't provide more than 1/2 your support for 2019

even if a test is failed she could still claim you if you are her qualifying relative if these test are met

1) your gross income for 2019 was less than $4200.   (gross income includes all taxable income and excludes nontaxable income)

2) she provided over 1/2 of your support for 2019

if you are her dependent the rule is you can't claim any dependents on your return.