Hard to say without seeing a pic of Twilight. She's REALLY hard to find loose in truly mint condition. If she's really minty mint mint with perfect flocking and unfaded curly hair, she could probably sell almost as high as she would MOC, maybe $75. With common issues of some flocking loss, dirtiness, and dry/faded/brushed out hair, her price would fall to around $20 - $45, depending on how bad it is.
I'd be interested in your loose baby accessories! Maybe $2 or 3 for the sippy cup, $4 - 5 each for the rest, though they can sell higher sometimes. I would take Canadian shipping prices into account when pricing.
Edit: As a set, the xylophone with mallet would probably be a little more, though I won a set recently for $4.11. The xylophones fade easily, so take that into account too.