On Frollith, I have been known to emote small water- or fire-type arcane/divine effects (and occasionally some big ones).  I've justified it through the religious spheres (water) and existing spells (flamestrike).  One Meissan mage used to always emote creating a red ball to play with, which I thought was awesome.  
Such emotes, when done in purely RP ways, can be cool.  Just make sure you have justification for whatever you do.
Likewise, emoting that you're carrying a baby is fine.  Emoting that you kill a baby is fine, too.  Where the baby-killing crosses the line is when it forces a particular action upon another PC.  For example, consider the following:
First Example wrote:
Meanie-head jumps in front of Mother, snatches the baby, and slits its throat.
vs.
Second Example wrote:
Meanie-head jumps in front of Mother in an attempt to snatch the baby!
Mother is caught unawares - her child is taken!
Meanie-head slaughters the youngling with a diabolical laugh.
The first example is poor, because the would-be killer forces his interpretation on the game without any check or dice-roll.  The second example is fine, because the Mother PC is given a chance to make the decision that negatively impacts her character.  She could likewise have chosen to evade the attack - thats the risk you take when using emotes instead of coded attack commands.