In the mid 18th century, in an effort to reduce the number of illegitimate children who were ending up as vagrants, criminals or in the poor house (and thus a financial burden)laws were introduced in England aimed at controlling this problem (which was probably not a little due to the widespread introduction of cheap distilled spirits). Under these laws an umarried woman who became pregnant was required to name the father of her child who was then given the choice of marrying her going to jail. If she refused to do so, magistrates would issue a document of shaming which she had, by law, to take to her parish church where the minister would read it out loud at service while the woman stood at the front of the church. Parson Woodforde's diaries contain a number of examples of these laws in action, on several occasions he married couples where the man was brought to the church by the local constables, in handcuffs.
Wives who did accompany their husbands were very useful to them, particularly in foreign garrisons where they could earn extra money by doing washing or growing vegetable gardens or raising livestock (mostly pigs as they are easier to feed) for sale. An eyewitness who lived in Halifax during the period recalls the soldiers' wives going from door to door selling peas and other vegetables, usually wearing dark blue, hooded cloaks (uniform researchers take note).
Soldier's wives could be problems in the field as they were not as amenable to discipline. Thorpe's memoir of the Corunna campaign contains a marvelous anecdote in which the wives were ordered to remain in camp with their children when his division made a march to contact against the French. The women banded together, hired a local guide, and actually reached the division's objective before the troops did. After that the divisional commander gave up trying to control them but unfortunately most of these women and their children died during the retreat in late 1808 and 1809. For this reason, wives were not permitted to accompany the Walcheren expedition and Rifleman Harris records seeing them wailing on shore while the boats took the troops out to the shore.
Wives in garrison were more easily disciplined as the penalty for misbehaviour was to be turned out of barracks and struck off ration strength. The memoir of Lt Thos. Browne of the 23rd has a marvelous description of the wives threatening not to let their husbands queues be cut when the order came down to do so in 1809 as a well turned out soldier, including a well-dressed queue, was a mark of pride for a soldier's wife. The battalion commander put down this incipient female mutiny by ordering his enlisted men to have their queues cut, company by company, in the barrack yard while the women looked on, muttering. However none of them dared to protest as he would have thrown them out of barracks.
As to the thoughts and beliefs of soldiers who left their wives at home or took them on campaign concerning such things as sexual assault, you would have to consult the diaries and memoirs of enlisted men who were in this position.
The whole question of sexual assault during this period is fraught with difficulty (as it is today). If you want to get a good idea of the context of the times in relation to this, take a look at the records of the Old Bailey Court in London which cover the period (if memory serves me right) from 1700 to about 1830 which are on the Internet. You can actually search these records by type of crime/charge and date. Most cases of sexual assault, then as now, did not make it to court and, of those that did, most were dropped because of lack of conclusive evidence. I have not got my notes to hand but as I recall a 40 year search of these records, 1775 to 1815, only turned up 10 or so cases where rape was proven and the penalty in all but one case was hanging. The exceptional case involved a man of good character and his sentence was commuted to transportation (to Australia) for life.
Generally, in the British army of the period incidents of sexual assault against civilians were, if discovered, punished severely. There were of course always the lawless acts of individuals (and there always will be) but, as far as I know, the only incident where several cases of sexual assault (and murder) took place, where the evidence was clear and the troops were under control, occurred at Hampton, Virginia in 1813. The fact that the troops involved were actually French deserters and prisoners of war enlisted in the British army -- which was used as an excuse by the senior British officer present -- was inadmissible. That officer by the way was Colonel Thomas Sidney Beckwith, late 1/95th Rifles.
I hope this is all of use to you. As I suggested before, if you contact me off Forum, I could give you more information that I cannot do on the Forum, lest the "Watchers," the Nazgul or Ringwraiths, that hover above us all, descend on me with shrill, piercing shrieks.
DE Graves