Female leads are their early 20's, male leads are about 10-15+ older:
The Story Of Ming Lan (highly recommend but ML has two kids from a previous relationship, never married though.)
Kincheed Radish Cubes (no love triangle)
Golden Bride (arranged marriage, no love triangle)
A thousand Kisses (secondary couple, no love triangle)
Family's Honor (secondary couple, some opposition from his family because of age gap and he is
divorced but no kids.)
Triumph In The Skies (love triangle but with the second female lead, ML falls for FL later.)
Dreams Link (no eng subs I think)
This are daily 100+ep dramas with FL in their 20's, ML in their 30's and early 40's.
Pure 19 (love triangle at first with SML, then she falls for male lead.)
A Good Day For The Wind To Blow (some opposition from ML's family, there is love triangle at first with FL's childhood friend and ML is the single dad of a 7 year old boy.)
Daring Women (FL is a young widow with a little girl and ML has grown kids though.)
It's a kind of hard to find dramas where the male lead is much older, but no divorce, widower or doesn't have any kids.