Here is my overly literal translation of 1 Peter 3:7

> Husbands: similarly dwelling according to knowledge as with a **weaker**
> vessel, the wife; rendering honor as joint heirs of grace of life, so
> as not to be hindered the prayers of you.

The operative adjective here ἀσθενής (asthenés) means literally "not strong", ie "weaker" but sometimes means "sick" or "ill".

The "weaker" meaning can be either morally (eg, Rom 5:6, 1 Cor 8:7, 9), or physically (eg, Acts 4:9, 5:15, Matt 25:43, Luke 9:2, 10:9).

Inasmuch as "weak" as applied to wives cannot mean "sick", it must mean either moral or physical weakness compered to men - and that is the point - the adjective is a comparison with men generally.

Therefore, I conclude that Paul is referring to women/wives being physically weaker than men.  There is no evidence that women are morally weaker than men at all.