Originally Posted by ramcewan
Other than the difference in focal length that has already been pointed out it's worth noting that the 14-150mm mark II is weather sealed and constructed of higher quality materials like the 12-40mm f2.8 she already has. The 40-150mm is not weather sealed and mostly plastic in construction.
If her camera body is weather sealed (E-M5, E-M1, E-M5 II and E-M1 II) this would make a big difference.
Not to say the 40-150mm is a bad lens, although I don't own one everything I have seen from it shows it to be rather sharp. Likewise the 14-150mm mark II seems to be very sharp and a capable all-in-one zoom.
From what I've read the 40-150 is one of the best bargains in the format. It's just not wide aperture, etc.