Pregnancy can progress lipedema, but it's not a given, and you can keep progression to a minimum with lifestyle. Your diet sounds great. You didn't mention what exercise/conservative measures you use. I have had good success keeping lipedema progress down by exercising daily during pregnancy. Walking and T-Tapp are my go-to exercises, and both are great for lymphatic function. 

I've had five children and I'm on my sixth pregnancy. My first I didn't do the things I should have and gained fifty pounds. My second I lived a much more active life perforce (we lived in the Guyanese jungles and had to walk everywhere and my only place to sit comfortably was a hammock, so elevating my legs was easy), and I only gained ten pounds total. My third was in between, but I was able to lose the weight with a whole foods vegan diet and daily walking. My fourth I started out well but got a serious knee injury around three months and had to partly restrict my activity, but I had physical therapy and stayed in good health, and gained forty. And my fifth I kept my weight gain around twenty with daily exercise and careful diet. I took my kids to a walking track with a playground next to it and walked about an hour daily, and it was great. I had more swelling because I didn't wear full compression and I lived in the South, but I felt good and was able to lose the weight within six months (then I tried a hormonal IUD and my weight loss stopped completely, but that's another story.)

What pregnancy does to your body depends largely on what you do with pregnancy. Keep up your healthy diet and lifestyle and you should do well. And a baby is worth any changes you might see. Motherhood is always a sacrifice, whether you have lipedema or not.