Sister is disappointed in herself

My sister is 16 weeks pregnant and she’s feeling down about herself . She’s having back pain, trouble sleeping , and other pains . She expressed to me she’s disappointed and thought she would be able to basically be better at being pregnant . Is there anything I can say or do to help her feel better about it ? I tried to tell her she’s doing a great job and she’s growing a human and that takes a lot out of us. But also didn’t want to say anything that would sound insensitive . I know there’s certain things I would probably get annoying or frustrated with if said to me so I don’t want to say them to her . It’s her first pregnancy . I can relate in away because my labor and delivery with my first didn’t go as planned and it’s looking like the next one won’t be either .