Eco-advice for painting floor

[flowers]

We have a redone attic which is where we all sleep. Since we've moved into the house there (2 years ago) there is this old, nasty wall to wall carpet which we've known we want to rid of.Circumstances led us to pull it up today and we were hoping the wood floors underneath were in better shape. They are horrible and are paint splattered and look varnished from another century. yikes.

Eventually we are going to put reclaimed barn wood flooring down, but we don't have the $$$ to do it now. Our interim solution was to paint.

Here is our dilemma:

If we use an eco-friendly voc-free primer we have to sand the floor. Sanding this old floor with old paint and varnish could potentially have lead dust everywhere. I am pregnant and have two young children.

We have this Bulls Eye water based primer that can go over varnish and rough surfaces. It is supposedly low voc. The ingredients I am concerned about are the acrylic polymer and the ethylene glycol. I would hate to be sleeping in a room full of toxic off gassing but I am no expert on any of this and from my remedial attempts at researching I became very confused.

What's the best option? What would you do?

[mumkimum]

Not really sure about your two options . . . that said we opted not to have our floors sanded (with dh's bad allergies & asthma) and I found a company called Mr. Sandless that, essentially, does a chemical peel over the floor to remove the old varnish and then a water-based finish. Their products used fewer chemicals and didn't have the long amounts of outgassing as other products do.
I have no idea if there is anything out there that you would be able to get and use yourself that would be similar, but it might be worth looking into.