My DD1 has, up until now, been very gentle and loving to her little sis (3) and despite normal sibling spats has been very good to her. Recently she has been talking to her like she is something she has found on the bottom of her shoe. DD1 will physically go for her if she gets in her way, or irritates her in any way. She will get DD2 to do her bidding if she wants something, even to the extent of treating her like a skivvy to fetch and carry for her. Is this normal behaviour or is there something else going on? I hate it because it is making me very protective to younger one, when we have previously been very close