Why did Lewis and Clark believe that the presence of Sacajawea's baby might have an effect on the expedition?

Lewis and Clark believed that Sacajawea's baby would have a positive effect on the expedition by serving as a symbol of peace and goodwill to Native American tribes they encountered. The presence of a woman and her child could help to foster trust and reduce the likelihood of conflict, as it signaled that the expedition was not a military venture. Additionally, Sacajawea's role as a guide and interpreter would be enhanced by her maternal presence, making interactions with local tribes more approachable.