Chose ones with colour pictures, broken up text, a larger font and nice line spacing. These make the volume far less daunting.
A lovely series to start with is Alan Ahlberg. He does 4 about the same family: The Children Who Smelled a Rat, The Man Who Wore All his clothes, The Woman who won things - and one other too. They are funny and nicely written, but in very short little chapters.
How old is your DD? Another series my DD enjoyed was Daisy and the trouble with... Again they are nicely spaced out and well presented. there are pictures too, although black and white. there are 4 or 5 I believe now. They are written in the first person - the writer being the 6y Daisy and written just as a 6y would wrrite/speak. DD really enjoyed these.
There are lots of ranges of books that are nice starters - Blue Bananas, Colour Young Puffin, Colour Crunchies, Read Steady Read, I Can read, etc.
There are lots more suitable books tht are far better laid out than RF, especially for first starting on chapter books.
My DD enjoyed Magic TreeHouse too but these are more along the lines of RF in terms of layout, so a lttle more daunting initially.
Often your local library will stock these first early chapter books. A great place to look.