It is HIGHLY unlikely that she would have such strong symptoms as a result of pregnancy this soon.
This is the hard part of infertility. The ups and downs of waiting. Pregnancy is hard to predict from symptoms. Truthfully, most women don't have a lot of symptoms for the first 4 weeks of pregnancy and they slowly increase after that. Nausea, for example, happens for most women around week 6 or 7 if they are going to get it. The reason is that the pregnancy hormones have to accumulate enough to cause the symptoms. That takes a little time. However, there are no absolutes. Some women say they feel pregnant pretty quickly. But those symptoms reported are usually very subtle like a little more tired than normal, breast tenderness and just feeling weird. A lot of women, myself included, would feel pregnancy symptoms when trying to get pregnant so I thought because I was hyper focused on my body. Every twinge or moment I would think about within my body because I really wanted to be pregnant. Kind of created psychosomatic symptoms for myself.
The only thing that is really going to confirm pregnancy is the test she will take.
Now, I also did temperature taking which gave a little extra knowledge. Women take their temp first thing in the morning before they get out of bed. Then put it on a chart. I just had a cheapy digital thermometer (under the tongue). The pattern women follow is that your temp is pretty similar every day starting on the first day of your period or cycle day one. Then right after you ovulate, your temperature rises about a degree and stays there. UNTIL right before your next period UNLESS you are pregnant. So, your temperature will drop back to the pre ovulation degree unless you've conceived and then it will stay at the higher degree. My temperature stayed high two times, I had two pregnancies. :>) So, if my temp was still high, I knew there was still a chance I was pregnant. Once it started dropping, I knew it was a failed cycle.
Let us know how it goes. That would be an excellent Valentine's gift, right?! And do keep in mind that only about 5% of women are not successful getting pregnant at some point. It may take time, work, money, etc. but with modern fertility in place, most women get pregnant.