After five months dating a wonderful woman, we’ve decided to move in together soon. We’re very much in love, but we know there’s a lot to be discussed/worked out before hand.
We each have a child (mine, shared custody, is 8; hers, full custody, is 11).
We’re both professionals with jobs, but a difference in salaries.
We both own our own houses.
We decided that she’ll move into my slightly larger house and rent out hers. We’ll each retain financial responsibilities for our own houses (mortgage, taxes, insurance, upgrades): neither one will be adding equity to the other’s property. But how do we split the expenses?
Should splitting common expenses (groceries, gas, electricity, cable, etc) be in proportion to our salaries?
How much “rent” should she contribute?
We both want to be fair yet make sure that the other is protected in the unlikely case things don’t work out.

- Planning Ahead

The only "sure" answers are what feels truly comfortable for each of you… even if others do it differently.
My approach is to divide shared household expenses proportionately to your salaries – e.g. if one of you can afford 2/3 to the other's 1/3, then each of you puts an amount into the bank to cover your anticipated budget, in that proportion.
I don't personally like the idea of charging a partner "rent." If you wouldn't normally be renting out the space she and her child are occupying, why would you charge her for it? I think it makes the other person feel temporary, and unequal.
Also, though her child may be occupying the house more than yours, if you're the higher earner, it'd be penny-pinching to figure out a dollar increase on that basis (or vice versa, if she earns more).
Presumably, each of you pays your own child's extra costs such as clothing. Since you're both retaining full ownership of your own houses, you're both "protected" in the event of a split.
If you marry, each of you should seek legal advice for a more formal pre-nuptial agreement.

When my son was in high school, he spoke to my husband about financing his university education. The answer: "Do what you can and we'll pay the rest."
My son hardly worked despite a light course load; whenever he needed money, he worked a few shifts at a grocery store. He slept or played computer games for years.
He's graduated, not working. My husband has no intention of helping him.
I agree that my son took advantage of us all these years. But he won't be able to make student loan payments, which will result in a bad consequence (default).
I want to help him, but my husband refuses.

- Who's Right?

Your husband is right, though it feels wrong. I say this from the experience of many people who indulged their children’s laziness and gave in to supporting them, only to find they were never free of their offspring’s unrealistic expectations, constant needs and demands.
It’s a tough call to leave your own child struggling, but it’s also a practical, direct lesson that comes from the child’s own experience, not just your warnings.
Yet, I also believe in a safety net, if it’s earned. Let him seek a loan, and either get refused or default. At that point, negotiate a deal: e.g. he gets a steady part-time job, and you’ll supplement the loan payments.
If he quits, so do you. His future is then decided by his actions.

I’m 23, completed a post-grad certificate in Environmental Management and Assessment, and did some travelling, of which I’m proud. However, my twin sister’s working on her PhD.
Whenever people ask about her, or if we’re together, they always direct comments to her like, “Wow, you must be so smart! " They ask her about her research, but I’m never asked about my program, or anything.
How do I deal with comments so hurtful? They make me feel inadequate.

- The Other Sister

Twins commonly face comparisons, and strive for individuality.
You’ve purposefully chosen a different path, had experiences your sister hasn’t known.
You could ask her to include you in those conversations… but, if that’s not a comfortable option, speak up – say, “yes, she’s marvelous in her field. I’ve been doing some different stuff I’d like to tell you about.”
Or walk away. These remarks are only hurtful if you let them be.