My wife and I dated for 3 months, then got married, but we were both on our second marriage and were in our 50s. We had some maturity and a background of miserably bad first marriages.
For younger people, 6 months of dating sounds better, but who can really regulate the development of romantic love?
I do not believe you can really know a person from just online interactions. You need to be with them in real life and do things together, noticing facial expressions, eye rollings, habits, reactions, tone of voice, posture, smiles, twinkles in the eyes.
I devised a 100 question form for us both to fill out, asking about favorite things.
Favorite hymn, Bible preacher, scripture verse, devout book, denomination, command of Jesus, leisure activity, restaurant, beverage, sandwich, dessert, fruit, vegetable, snack, color, flower, animal, pet, season, movie, type of music, artist, fashion style, outdoor activity, color, fabric, childhood memory, etc.
She filled out the form, I filled one out, then we read each other’s answers. This is a fast way to get to know a lot. Most of it may seem superficial, but knowing little things about someone can give you good insights for gift giving, and so forth