I love this image, so cute but can't quite make my mind up about the story behind it.  LOL, yes. I do make my own little stories up about the images while I'm colouring the.  I just wonder why 3 small children would be huddled together.  Perhaps the tallest girl is in fact the mummy?  Ah well....I can't but help to think that something not so happy has happened and the 3 people in this image are all children, perhaps waiting for mummy or daddy to come in and say everything is okay.
Right well, less about my thoughts!

Pens used for tallest girl.......
Hair TN3, EB3, EB4, TN8 & BG6 as advised on Crafter's Companion lesson sheets for hair combinations.
Nightdress & Hair band: LY1, CT1, CT2 & CT4 (my own choice)  These 4 colours did seem to blend well.
Skin:  TN1, TN2 & TN3

For baby and small girl
Skin: FS1, FS2 FS3....Cheeks: FS6
Baby's suit: BT1, BT2 & BT3
Hair:   TN3 & TN5
Small girl's nightdress: PL1, PL2 & PL3

I usually use either Hunkydory's perfect stamping, super smooth 300gsm card or Crafter's Companion 216gsm Ultra Smooth, Solar white Neenah card.  I do find some bleeding with the latter.
I also have a wad of cheap copy paper under the card I'm colouring onto.

With all areas I'm colouring (small areas at a time, helps blending as ink will still be wet)  I start with the lightest colour, saturating the area.  I then use the darkest, working up back to the lightest.  Particularly with hair I use the lightest colour to remind myself where the light will be coming from, sometimes I'll leave those areas colour free and only cover those areas right at the end to enhance sunlight shining onto the person's head.  (Something I'm still working on)
Where necessary, I'll go back with the darkest colouring with fine flicks to pull out the movement.

The little girl's nightdress I chose to go straight in with the darkest colour (PL3) following the lines on the dress.