although having one bank statement being overdrawn is probably not enough to refuse your visa, if they there are any other concerns then it could be used as one of the reasons for refusal thou probably not the main reason.

should not be a problem with your mom sponsoring your acommondation, as long as she can get a letter off the housing assication saying its ok with them,

does your mom have any savings? or her sister ? might be possible they will allow 3rd party financial support...

she needs to pass the english lang test then apply for the visa then the cfo

you must have evidence from b4 you married? and on your trip, pics, letters, receipts, etc ?

i would save up for the visa, if you have £1,500 then its better than 0
remeber the cost of the visa is what around £650+ and the cost of the flight might be £400-£500 so thats most of your savings gone

good luck tony