She has horrible symptoms during the term. Her last baby had her on bed rest and she LOST weight rather than gained.
What can be done if anything about the following?

Nausea-all day
Diarreha-severe
Faitning Spells
Heart palpatations
Headache
Intense aversion to smells
Overall body and muscle weakness

I am willing to try many things for her not to suffer as she did before.

Well, unfortunately a lot of these symptoms just come with the pregnancy territory. Her doctor will best be able to advice her on things that she can do, as her doctor best knows her present state, and her previous medical backgrounds. However, nausea can be helped by keeping a small amount of food in her stomach 24/7. hard to do when nauseous, but really the nausea is usually do to low blood sugar.(this is why it is usually referred to as morning sickness. While it can happen at any time of the day or night, it tends to be worse in the morning when you have gone all night without eatting, therefore your blood sugar is lower) having really bad diarreha is common, particularly in the beginning. However, it should be reported to her doctor, as any severe symptoms should be. Drinking lots of Gatorade will help. It is packed with electrolites, and these will really help to replenish her and keep her hydrated. Very important, as the diarreha will dehydrate her, and she needs to stay hydrated for herself and baby. Fainting spells are also common, due to the change in blood flow and heightened hormone activity. Particularly after sitting or laying for a long period, then standing. She needs to rise and sit slowly. Try not to stay on her feet for prolonged periods, and this also goes back to the low blood sugar and hydration. If she has low blood sugar or is dehydrated, it will be much easier for her to faint. Heart palpatations could be due to the increased blood volume and the hearts need to work harder/faster. Could be do to several of the other reasons here as well. Headache very common, due to these other reasons, as well as the increased/changed hormone activity. The intense aversion to smells definitely comes with the territory and I am afraid there isn't much she can do about that, other then to try to avoid them. Trying to eat and drink things that are blander in taste and smell will help. The over all body aches are, again, with the territory. They will only get worse as time progresses and she gets bigger and more awkward. Taking warm baths(as long as okayed by the doctor, and as long as the water is not too hot) can help soothe the aches. She will just need to be careful getting in and out. I think it is great that you want to help her. Any fears or concerns that she has should be discussed with her doctor every visit.(or even between visits)they work with pregnant all day long and can give the best, medically safe for each individual, advice. Good luck