I felt like Nala knew they would follow her anyway to catch up with Simba, given they are his buddies. She wasn't being harsh in this situation. This sort of makes me wonder about the conversations she and Pumbaa had later in the Pride Lands inbetween the ending of the original and "Simba's Pride". Timon too.
When the Pride Landers confronted Zira and young Kovu in "Simba's Pride", I saw Timon and Pumbaa standing right beside Nala, which makes me think whatever issues were going on have long been sorted out and that they respect one another.