Someone I know who has sworn oaths binding loyalty and service to another seems to be running into a conflict between those solemn promises and a love relationship, especially because the liege doesn't seem to like the lover for whatever reasons. How might I advise her to ease the conflict?
An interesting predicament, my friend. The concept of sworn service and binding oaths is quaintlhy archaic to many, but deeply profound to others. I suspect your friend, like me, takes the giving of oaths quite seriously. Otherwise she would not consider her situation to be a conflict. However, last I checked oaths of fealty do not extend to affairs of the heart. Unless she specifically gave up her right to determine with whom she might associate then, in this tiger's opinion, Lord Huff-n-puff has no say in the matter.
She may value her liege's opinion and desire his approval, but such are not neccessarily prerequisites of service, or at least they should not be.
She may want to discuss the reason for His Lordship's apparent dislike of her betrothed, but in the end she will need to determine if her relationship in any way prevents her from serving her liege. I suspect it does not. If it does, or if Lord Huff-n-puff makes it a condition of her service, then, again only this tiger's opinion, she may need to either re-negotiate the terms of that service or reconsider it all together.
One final editorial comment. No employer/Master/liege worth serving would impose such restirctions on their employees/servants/serfs.