The Panasonic FZ1000 has had very good reviews ... The zoom only goes to 432mm (in 35mm sensor terms) ... If she wants a longer lens the FZ200 goes to 600mm.
For birds, it can be important to note that the FZ1000 has a significantly higher pixel count of 20MP vs 12MP, (and each pixel is bigger), so there is more cropping latitude. One way to think of it is that when FZ1000 images are cropped to match the 12MP of the FZ200, its FOV is the equivalent of 558mm, so at the level of "details revealed on the bird" scarcely any less than the FZ200.
Also, since I find it very hard to keep a moving bird in the very narrow "600mm equivalent FOV" of my EM5 with 300mm lens, I like the idea of using a somewhat wider FOV with more than enough resolution, and then cropping to the framing I like.
Panasonic also boasts about the faster AF of the FZ1000 compared to the FZ220, due to its "new linear motor" and "new Depth From Defocus technology". To quote: "ultra high-speed AF of approx. 0.09 sec (wide-end) / approx. 0.171, sec (tele-end) is achieved."