My partner has a 2013 Fiesta, and has a habit of flattening her battery by sitting with the engine off, the ignition on, hence the drl are on.

Is there any way of disabling the automatic feature of the drl being on under these conditions, as I am getting tired of driving out to give her a jump-start.

 

There is nothing in the handbook about it; nothing in the lcd display appertaining to it; and no obvious way of doing it via the light switch(es).

In short, No.

Are they LED or bulb type DRLs?

It might be that the battery is getting tired so it's flatenning quicker than it should.

I agree, get the battery checked out especially as winter is approaching. You say she sits with ignition on, but alas you don’t say for how long ? If it is a short time I would definitely have both the battery and alternator tested. 
 

you could trade her in for a newer fresher model…….  Let you decide if it’s the car or the girlfriend 😂

It's bad practice to sit with the ignition on without the engine running for various reasons, first thing I was taught as an apprentice motor vehicle technician.

No.

My son used to do this, until I made him sort it himself.

They don't listen until they have to sort it.

 

1 hour ago, billyboy said:

It's bad practice to sit with the ignition on without the engine running for various reasons, first thing I was taught as an apprentice motor vehicle technician.

How long ago?  On old cars I was told this was bad practice because it was heating up the ignition coil if the engine was stopped in a position with the contact breakers closed.  You didn’t know if they were open or closed.  I don’t know if there is any good reason not to do it on a car with electronic ignition. I’m not saying there is no good reason, I just don’t know.

1 hour ago, isetta said:

I’m not saying there is no good reason, I just don’t know.

There is no good reason, sitting with all the accessories running kills the battery

LOL, this is the exact reason when I installed my own DRLs that I had an interior cabin switch put in so I could switch them off. However, it is mandatory that when they are 'factory fitted', you can't switch them off. 

I often sit in the car for lengthy periods waiting for her to complete some retail therapy, listening to the radio, and have experience (not in this car) of doing that, and when restarting the car, had a flat battery...

Sit her down and explain to her that she wouldn't have the central heating on and leave all the doors and windows open in the middle of winter.

Just ensure she is in a good mood and you have a tin hat on 😄

I doubt it's the LED's flattening the battery.  It's all the modules that are being kept awake with ignition on.

Education is the key here.