Hi there, I need some urgent help with a canceled flight.<br />
1) Keep an eye on flight availability to CDG - this is usually a fast moving situation so availability will pop up at any time.
2) You're only allowed to make one change - ignoring automatic changes. This can be over-ridden in certain circumstances by a supervisor, but it's best not to accept an imperfect outcome given point 1.
3) EC261 right of care applies, so if BA don't book a hotel for her, she can do it herself, best not to spend £200 for the hotel, and keep taxi fares under £50, but these are guidelines rather than rules. She can also claim reasonable food, drink and communication costs, but best steer clear of claiming alcohol. Keep and photo the receipts.
4) You are also allowed to reroute via (e.g.) any LCY-ORY service or LHR-BRU + train, anything within 300 miles of CDG, but on paper (but not necessarily in reality) any additional transport costs are for own account.
5) Detailed guidance on EC261 can be found at the top of the thread.