Here are a few real world examples with which I'm acquainted.
Family [A] 13 children; age 26, male, married w/1 child, has own HVAC business, wife stays home, age 23, female, single, community college PT/restaurant hostess PT, age 20, male, single, lives overseas w/relatives while attending university, ages 17, male & female twins, finishing high school on-line, both work for oldest, age 16, female, attends nearby state school for deaf, age 14, male, just graduated grade 8 from non-denominational "christian" school, accepted to all boys Catholic high school, does odd jobs, home repair, etc. in neighborhood, age 13, female, attends same school as 14 y.o. brother, helps at home, age 12, male, same as next older sister, age 10, male, age 8, female, age 6, male, last three home schooled by live-in aunt, age 1, male, proud matriarch manages home and children along w/her daughter-in-law. Father is renowned medical researcher for international agency. Paternal grandparents, maternal grandmother, single, older uncle, all live in a "barbell" type row house in ethnic neighborhood of major US city. Parents, grandparents, uncle, oldest son, possibly his wife are foreign born. I believe grandparents own numerous rental properties.
The small backyard is a vegetable garden. They keep some chickens for eggs.
This family has lots of support from ethnic community, relatives in US and overseas. Father has well-paying job. Let's face it, most Americans don't have these social advantages.
Family (B) 11 children; age 30, female, single, spec. educ. teacher, lives home, age 28, female, in college/working, lives on own, age 27, male, married, lives overseas, age 23, female, married lives out of state, age 20, single, lives on own, age 17, male, in last year of specialized (competitive) high school, works PT as part of schooling, age 16, female, all girls Catholic high school, works in library PT, age 13, male, age 11, female, age 8, female, latter three attend privately funded charter school. Mother is Director of the charter school; father works for state dept. of public health. Large home willed to them from his parents, so no mortgage. Also live in ethnic community in major city, also have extensive family network here and overseas.
Family [C] 16 children, age range 28-9 includes 2 sets of twins, still living at home, 14 y.o. girl twins, age 11 boy, age 9 boy. Mom had to have surgery, so there'll be no more. These are Old Order Amish farmers. Mom's parents live in attached 'dawdy-haus.' Obviously, this situation is unavailable to most traditional Catholics.
Family [D] 7 children, no. 8 due in July, age 13, male, age 12 male, age 10, female, age 8, female, age 6, female, age 5, male, age 2, female, almost-arrived baby, a boy. Dad works in sales for upscale retail chain---is often away on business. Mom had been working PT nights as a home health aide. Two eldest boys attend trad. Cath. academy, Mom and grandma home school and care for the others. They live on family "farm" in second house. Grandma's son #3 of 10 owns land, farms some, rents, boards animals, has construction business. He and wife have one adopted daughter. (They're medically unable to have own children.) All but father are cradle tradCats. Dad was in foster care "homes" from age 3-16; at which point he ran away due to neglect/abuse. He attends Mass when he's able and is supportive of his family. Everyone continues to pray that he'll convert.
Family [E] 8 children; age 17, male, in spec. educ. day program, has mental age of about 7, twin girls, ages 15, age 14, female, has mild mental retardation, age 12, male, age 11, male, has cerebral palsy, age 9, female, age 7, male. All but oldest are home schooled by unmarried aunt. Mother had a heart attack three years ago and cancer necessitating a hysterectomy. The girls do all the housework. Father has also had a heart attack, but works driving a delivery truck for a local food business as he's able. They're on disability and live in a house donated by a family in their chapel. They have use of a donated minivan and the county supplies special transportation for their physically handicapped son. They're able to have a vegetable garden and keep chickens. Between donations, part-time work, social services, and doing without the so-called necessities of modern life such as TV, cell phones for everyone, vacations, eating out, new clothes, etc., they get by. Mom and Dad have cell phones. There is one desktop computer for everyone. They wear hand-me-downs, go to yard sales, thrift stores.
While many, if not most tradCats look down on people like these, one thing I can't fail to notice is that love is not absent in this family. The children are well-adjusted and respect each other and their parents. Despite poverty, their door is always open to guests. They share that which they have and don't worry about what they have not. They have the blessing of living close to a chapel, so are at Mass nearly every day.
If Our Lord deigns to give a couple 15 children, He'll supply for their needs. If it means being poor, He'll supply the graces necessary to be poor. Of course, that entails the parents having great faith, trust, and cooperation with Grace.