powder normally means you need to work on your behaviour since powder is normally fine. a woman turning into powder though, when a male dreams of a female they do not know and they are not attracted to, it means they should try imbracing certain aspects that are normally deemed 'feminine' since they're falling out of balance with there natural male and female aspects. so perhaps her turning to powder means you're loosing touch with a female part of yourself and you need to focus on it. it could be an emotional thing, or maybe you should clean your room lol joking.
the turning into powder, was it like she disintagrated, or decayed, or was a litteral transformation? each has a different meaning, so it's hard to pinpoint which one particular is the correct interpretation.
a jar represents a womb, so that coinsides with the whole feminine aspect thing. the house is normally yourself. a dollhouse mind you is differnt, it represents a vision of an ideal family or life, where a house is you and each level a differnt level of your subcontious.
finally the island, it could mean a couple things, you need rest from the stress of your waking life, you're in a rut and need change, or you feel isolated and cut off from friends and family.
personally, i agree with the above post, meditate, but another thing you should try is making a dream journal, the second you wake up, write down everything, you could write in any order then put it in the correct order later, but get it all down in the most detail. you could also draw or vocally record your dream if you feel it best. if memory serves, 90% of a persons dream is forgotten in the first 5 minutes.