I do my best, and ignore the rest. I always put butter or olive oil on food (if it were a big meal like thanksgiving and knew they wouldn't have real butter (cheap butter is fine at relatives house) only some form of margerine, I would bring my own, but if I was just going over for dinner, I'd probably just not eat the margerine, etc.
If they cook something with margerine, or unsoaked grains, I eat it (though margerine, I do try to avoid at all costs). If their meat isn't top quality, no harm.
I feel that eating and spending time with family is more important than eating TF all the time. If I were staying with relatives, I would bring/buy my own food/food for both of us for most of the time I was there. (For instance, I would definitely bring breakfast if I were going for a few days. And maybe some lunch stuff, and offer to cook dinner once or twice.) And let them cook what they eat for dinner once or twice for us.
I also don't have a problem saying no to dessert though, or having only a small bite.
If your mother wants to make you gluten free brunch that isn't soaked, if it isn't going to cause an allergic reaction, let her, I say. If she wants to have brunch with baked goods every week, you could suggust that you could make it together, get them soaking, and then make it together, and she can learn how you bake.
For a long time I tried to teach my family, but I realized two things: 1, you almost always come off sounding preachy, and like you think you are better than them for eating how you do, and nobody likes to feel/think/hear that.
2, I can't change how they eat, or change them in any way. I can tell them how I eat, but it may cause friction, and it may be better for our relationship if I stop trying to get them to eat how I know is better, even if it means watching my mother with thyroid issues eat lots of processed soy and aspertame even though she knew when we were kids it is bad, and my father eat margerine and almost no real fat, and my vegetarian sister eat almost no animal fat.
I only talk to them about how I eat when they express interest (like my sister often does, I'm happy to talk about my learning/knowledge of what is healthy, without becoming preachy about meat, focusing on what is good in her diet that she could eat more of, and the few worst things that would be easy to cut out). It's hard, but our relationship is worth more than trying to change what they eat knowing I can't. And part of preserving our relationship is respecting their right to eat what they want.
(I will not however, eat pork or shellfish at a relatives house, or meat and dairy together, and they know that I keep kosher like that. To me, being gluten-free or allergies is like that, something that shouldn't be compromised. If they won't accept it and work around it, it is perfectly acceptable in that case to bring separate food that you can eat and enjoy it at the same time/same table.
Sorry if that is long and blabbering.
