In two words, you betcha. A pregnant bridesmaid is not a big deal unless she goes into labor while walking down the aisle, in which case it makes for a fun and exciting wedding story. Yes, pregnant bridesmaids are not exactly tradition, but that hardly matters in today’s world. It is very, very, very rude to ask any member of the bridal party to step down unless it is for an emergency or something horrible happened that makes you not want to be friends with the person anymore. The latter is particularly unlikely, as bridesmaids are generally the siblings and very best friends of the bride.
Talk to your preggo bridesmaid, as she might need special arrangements so she can participate in the ceremony and reception. She will need a dress with a maternity cut as well as flat footwear so she can stand comfortably when she needs to. Ask her if she wants virgin versions of alcoholic beverages or is comfortable with water, juice, and iced tea.
Your pregnant bridesmaid may step down due to exhaustion or self-consciousness, but if she wants to participate in the wedding, let her! Telling her she can’t be in your wedding because she is pregnant is just plain mean. Be a good friend and encourage her to stay in the wedding party!