Question when to start..

BritClen

DD with be 2 in a couple weeks and I have everything ready to go with PTing....I am just unsure on when to start....

she is showing signs...

she ask to go potty...we take and she does nothing....

she can pull down her pants and pull up 

and she hides everything she has to poop..

The thing that is holding me back is the fact that a her baby sister will be here in two months...and I am wondering if that is too much change for her all at once...if I could put off PTing till after the new baby is here or just try now?