As always, get physician approval for her to continue working out at the same intensity. You may even want to give your client a copy of a workout you’re currently doing so the physician knows what intensity, frequency and duration your client is currently working out at. For most women who become pregnant they can continue to workout at the same intensity.
As her pregnancy progresses, you’ll want to be able to modify her workout. Taking out higher impact exercises for lower impact ones for example. You’ll also want to keep the lines of communication with both her and her physician open through the duration of her pregnancy. You mentioned that she just found out she was pregnant, so she may still be grappling with the fact that she’s pregnant, not wanting her lifestyle to change, not yet experiencing any pregnancy symptoms. That an change quickly. I often ask my pregnant clients how they’re feeling before we start, any adverse effects, how did they tolerate the last workout, how are they sleeping, Eatting, about any info from their last doctors appt., etc. Be prepared to change the workout at any time. The more you know about how they’re handling the changes of pregnancy, the more you’ll e able to help her with her desire to continue working out.
You’ll want to watch her heart rate, be sure she’s not getting over heated and that she’s not overdoing it. Watch flexibility with hormonal changes as women who are pregnant tend to get over flexible in their lower limbs in prep for birth. As someone else mentioned continue to train her core and transverse abdominals as these are important to support the growing weight of the baby.
ACE offers some great prenatal CEUs. A good book is Fit to Deliver by Karen Nordahl (there is also a CEU option with the book).
Good luck! And have fun!