At least one of two rather unpleasant things is likely to happen to a faithful wife who does not receive the assistance she needs.
1. She will break down. She will become clinically depressed, have crippling anxiety attacks, or otherwise become unable to function. She will require medication and/or therapy of some kind. This will put tremendous strain on the household which might demonstrate exactly what Mom does and why she fell apart. (NOTE: although a lack of marital support can cause a breakdown, a breakdown does not necessarily indicate a lack of marital support. Duh.)
2. She will withdraw. She'll decide it isn't worth it to keep asking for help and will stop relying on her husband. She will still respect and serve him as long as he provides for the family's basic needs, but she will no longer adore him, and they will grow apart. She may be able to redirect her affection to the children, and they will replace him as her primary source of affection. Or she may become dull and defeatist or hardened and resentful, fulfilling her tasks perfunctorily and minimally while holding onto the hope that once the children are gone she will be mostly free. The husband may consider this a relief in the short term, but eventually he will find that even though she's still there, she's no longer there for him. This may take a long time--she wants to adore him, so her heart will resist. But it will empty as she learns that although he is obeyable, he is not adorable. (And after all this--she may end up going the breakdown route, too.)
I think the CSPP bloggers have established their credibility in the Doctrine of Woman department pretty definitively. So I hope I won't be accused of being some kind of feminist creeper if I say that "traditional" roles can, like anything else, be caricatured in damaging ways. A wife who is dependable in carrying out her marital and maternal tasks in accordance with her marriage vows and the Scriptural ordering of family life deserves a response when she asks for help. If the family doesn't have a willing grandma or other volunteer assistant very close (less than 30 minutes away) and very available (most of the day, most days), the husband simply has to pick up the slack or the wife will break, whether suddenly and spectacularly or slowly and quietly.