take your pick, as many have, and decide if Mary was making an innocent referrence to having seen enough of the navy, or to sodomy. I personally think it was the latter. Jane Austen having brothers in the navy, and being one of only two daughters in a large family that ran to males, and at least one very worldly sister-in-law, would IMO be familiar with the reference. And, as pointed out above, this was NOT the Victorian era -- things were still looser in terms of references to sexuality. However, Fanny was only nine when she came to MP, so I am not sure if she would be familiar with the issue. It is quite possible that the family decided to put the best spin on the remark and not take it as a sexual pun.