Answer to your title question: She is lazy and you are out of line.
Just a few phone calls to organise the building of a house?? I wish!!! It's a nightmare job - which is why most people pay a professional to run the job. I'm in the middle of organising renovations (easier than a whole build) and the process is exhausting. Besides, the average tradesman is unreliable - and I doubt the average 23yo with no work experience could handle bullying them to turn up and do the jobs.
She shouldn't be sorting out your house for you. It's your house and you need to make the decisions. Let's face it, if the two of you break up (not an unlikely scenario) you'll want the house to be decorated in your style. And what design / project management qualifications does she have anyway? You should not be giving her a first job - she should be out seeking it on her own.
Of course, if you haven't got the time or inclination to build a house, then don't let her bully you into it.
Lastly, make sure the house is in your name only. Do not put her name on the mortgage unless married to you. And don't marry her till she shows that she can find a job.
Last edited by basilandthyme; 28-08-13 at 04:06 PM.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.