Books like Only a Promise
Mary Balogh
Only a Promise is 409 pages, about 7 hours 30 minutes at 250 words a minute.
12 books to read next
How long each takes
Persuasion 4.9 h 
The Grand Sophy 6.3 h 
Lady of Quality 5.2 h 
The Corinthian 4.5 h 
Friday's Child 6.9 h 
The Secrets of Sir Richard Kenworthy 7.0 h 
The Toll-Gate 5.3 h 
A Civil Contract 7.2 h 
Regency Buck 6.4 h 
Cousin Kate 5.9 h 
Frederica 7.0 h 
The Reluctant Widow 5.2 h Bar height shows length. Estimated at 250 words a minute.