Bike loan in paris

We are embarking on a ride in France in September. Our daughter, a recent Cambridge graduate in the UK, wants to join us from Paris out to Giverny and then on down to Blois and needs to borrow a bike in Paris preferably at mates rates. We have our own bikes and will be riding down to Bordeaux and back but she just needs to ride to Blois and then back on the train. Any help or advice would be much appreciated. Thanks