what is a baby girl brat sub.... well that is a good question..and it takes a bit of time and understanding to figure that out..i will try to fill you in the best i can...i can talk better than i can type so i get a lil carried away.
ok first of all  you have a person with different facets or personas if you will, to thier personalities, no not a split personality not duel or multi even... just One with one or more levels, as a rule and please note, this subject tends to break all rules, but as a rule there are 4 levels to the BGBS( baby girl brat sub) and these are not in any certain order, however some tend to develope patterns with these levels...she is a woman first, she sees herself as wife mother, daughter sister, a coworker, a teacher, a nurse or what ever area she places herself in for support, friends or just as her nature dictates, being helpful.Second you have the submissive, the one yerning to please to serve to help to be loved and cared for on a deeper level, to be guided and taught, with a loving firm hand of a Dominant Partner.
Third she is the brat, she is a know all, i can do it all by myself,  move over here i come type of woman.. she is for the most part on the go,  here and there at the same time, burning the candle at both ends so to speak, she will sneek up on you and pull your undies up your back, she will blow raspberries on your tummy when you least expect it..she is a true lover of practical jokes and nonsense, and my all time favorite is the wet willies...see bottom for foot note how to give a good one..she too has a desire to be loved and accepted for who she is and how she is, her need for love and acceptance and fear of rejection some times  brings her to  use a tough girl shield, she loves attention and will do almost anything to gain it.. not caring the outcome even if it is negitive attention..so by giving her enough positive attention is a key in keeping the brat sub well ballanced and happy finding the right mixture of attention and  dicipline can be a Doms nightmare or His pleasure depending on His views. She is just like a little girl, wide eyed and wondering.. and for the most part she is wondering what buttons she can find and push  without actually getting herself in hot water..she strives on set boundaries and she will push and test them at times to make sure they are firm and you are in control, showing her she was right in choosing you, and that you are worthy of her gift..once  her hard earned trust is won, she may run from her own shadow at times but she will fight the world for those she loves. dealing with a brat  one will have to harden them selves a bit to keep doing  what is in her best interest...and to even punish her when needed.. with a lack of  dicipline/punishment  the brat sub flaunders and looses her direction and her focus and if you set the limit and she knows you will not enforce them she will soon loose respect and wander away.. she needs to know that you care enough for her to set that limit and enforce the outcome should she not follow..there is a time for play and she will always try that first because she loves to play...and there is a time to show her you mean what you say.. she will thrive and ulitimatly  the Doms reaps the rewards with a happy healthy devoted submissive  who has a high self esteem and better focus to complete her tasks..
and we have the baby girl.. this is the most vulnerable side of the woman.. this side is rarely seen if ever, and in almost all cases totaly non sexual, times of strife and stress tend to bring this level out more than anything, when she feels out of control hurt scared she is like a very young child some may even have child like speech and behavior she needs love attention and devotion from her Dom, He must be willing to give her the time she needs to feel safe and secure once again in his loving care, i advise not to even think dicipline in this case the harshness may be to overwhelming for her to even comprehend, tenderness is the key in this case..when in this mode or level she is showing you her most tender places her true loving trusting  heart..treat her lovingly and tender as you would a small child and she will reward you with a deeper devotion and love and a trust that is endless... treat this part of her unthinkingly  or harsh and she will withdraw emotionally on all levels...and you will forever loose a great part of her...and the chance to fullfill a deep need in her.. to be loved unconditionally without fear of rejection...all she needs is  her Daddy Dom
here are a few discriptions of the different personas found rolled up to make the baby girl brat sub... note not all will have these and some may have one or more  but this is just a general guide.
a "WET WILLY" is done first by spotting a victim..hmm i mean playmate..grins... an all unsuspecting one is best of all...you take the  index fingers of both hands and put them into your mouth... slobering them up really good... the wetter the better...and slyly sneak over to the victim...errr... playmate... and stuff your wet fingers in the ears twisting them in as far as they will go without hurting the person... then YELL..."WET WILLY" then run like a brat outta hell!! that is the proper way to give a wet willy :)