I'm not sure if this is affectionate, but it's more personal. 

Mother would most likely be Okasama, or okasan. Also when speaking about
someone else's mother... example, Jiro no okasama wa kawaii desu. Jiro no
(being jiro's as no is usually a possessive marker) okasama or okasan is
mother as we all know. and kawaii being kute and desu being is. So the
statement reads Jiro's mom is kute. Now, if it was you're mother we're talking
about. I mean you're as in you're talking... it would be haha wa kawaii desu.
Mommy is cute. Haha is used when describing your mother. Note that the
japanese usually show affection with a great deal of respect. So if you're
talking about someone else's mother that probably raise you, you might use
haha, being that you see her as you're own, or use the suffix, sama for great
deal of respect. as for okachan... I never heard that used before, and I
defiantly would never call my mother taht infear of a mallet. but then again,
I'm american born so too alot of azns, I'm stupid because I'm americanized.
well ta ta
												Maggy