same Jack has started going thru a lying stage as well not excusing her behavior but I too think its part of their development at this age

she coudl feel threatened that you have a partner now...I know its not the answer to all but have you tried spending some time alone special time so she realises just because you have a partner doesn't mean she is being shut out also as Missem said maybe DP could spend some one on one with her ....

((GBH)) here anytime for a chat Rach