I never thought that I would hear myself say this, but 'it depends'.
I am getting back into the field, and have to re-establish a track record. Through my market research, I have found an organisation that is directly involved in the area & one of the sectors I write in. They have requested for volunteers, and I will likely conclude the second meeting with the person responsible for the website run by the larger organisation in which he works.
I am a seasoned writer & with much credit behind me--but still not enough. We are still to finalise how we will co-operate, but being with them will enable me to develop skills that are lacking in a number of areas, and a chance to develop for a job in one area, down the road. It will also provide me another benefit--a chance to get out of the house, to socialise, and to network. In the meantime, I have let this chap know that I have limited time, as I have to freelance in order to survive. I go into this with my eyes wide open-a lot of unknowns, perhaps a sharply limited total duration, & a foot in the door, and an opportunity to (hopefully) find something suitable that pays. This is the way it is. But, I have learned through hard & painful experience, always make sure that you get what you want or need, and always with a distinct goal in mind. Be very careful whom you volunteer for. (Avoid most independent filmmakers--they're real shits!)
This flies in the face of what many, especially in the US, consider a positive attitude. But, this is the ultimate nature of networking, and in this situation, a fair exchange--they are trying to get the maximum from me, at no cost, & a chance to develop it further so as to attract more investment. He did not make any mention of even possible payment for a full-time editor or such. In turn, I am trying to get maximum ROI for minimal time. We both know and tacitly acknowledge this.
So, my message to you is, yes, if there is some tangible benefit for you by writing for this woman for free, then do it. But, set limits at the outset: amount of time you can commit, or articles able to commit etc. And, you will have to network like crazy to capitalise on this. But make sure that it clearly fits in with your larger plan. For older blokes like me, time is of the essence. If you're young/younger, then you might be content to go with the flow that comes from the experience or opportunity.