Anyone familiar with electric and manual wheelchairs?

I am trying to help my mother find a very lightweight, small electric wheelchair for inside my her home—something that will get in and out of ordinary sized doorways. She had a merits that she returned because it didn’t fit her well (the seat was only 16 inches deep and she felt she was falling out). She needs something with at least 16” wide seat and 17/18” deep). She is also looking for a non-electric/manual wheelchair for outdoors. She wants something very lightweight. Any recommendations? Thank you!