A test taken in the still of an early autumn morning last September confirmed the suspicion that had been churning in my stomach for weeks. I blinked at the little lines in the test window, shook my head and smiled. I leaned against the cool bathroom wall as a wave of joyful nausea washed over me. Just 13 months after welcoming our youngest daughter, our family was growing again.

I was careful to take the test after my husband left for work and I was psyched to surprise him with my little discovery when he got home. The day was spent cheerfully setting the stage for the big announcement. I got dressed up and perched my camera phone on a shelf at just the right angle to capture the moment. It all was so exciting! But as I imperfectly scrawled "Big Sister" in puffy paint on a tiny purple t-shirt, I felt an odd pang in my heart.

I glanced up from the paint to watch my daughter play. She toddled around slapping the colorful keys on her tiny piano. She seemed too small to be a "big" anything at that point. It felt like only yesterday that we celebrated her first birthday. It was hard to imagine her as anything but the littlest.

My oldest daughter had us to herself for years and years but it seemed our baby wouldn't get to be the baby for very much longer. Was it fair to push her out of that role so soon? The feeling quickly faded into the excitement of my announcement and my pregnancy progressed. My daughter and I lived the next several months secure in her reign as the baby of the family.

A shift happens when kids approach the 2-year mark. They have come so far since their newborn stage and the same child who was learning to crawl not too long ago now goes down the slide at the park. They develop physically and mentally in such a short time and are suddenly encouraged by everyone around them to be big kids. Independent and curious, my toddler plays the "big" role well. She feeds herself her lunch, practices using the potty and knows letters and numbers.

Yet in so many ways she is clearly still a tot. Still falling asleep in the shopping cart at the grocery store and babbling sweet half-pronounced words only I understand. She still stomps and wails when she can't fully express herself and looks to me with those big brown eyes for comfort or approval. Even though she is going to be a big sister, she is still my baby.

The morning of my C-section, I brushed my hair in the same bathroom that I discovered I was pregnant in all those months ago. The time had finally come for the new baby to be born and the reality of such a huge change was sinking in. My daughter's time as the baby was officially up. Another pang struck my heart.

My reflection in the mirror blurred as hot tears filled my eyes. Though we had spent months preparing for this change, leaving my toddler home to have a new baby felt difficult. I worried that she would be hurt; that she would be upset at someone else taking up space in my lap, in my heart. It all felt a bit like a betrayal. I worried that she wouldn't be ready but at that moment I realized it was me that wasn't ready.

After a teary goodbye, we arrived at the hospital for admission. Later that day our baby boy was born. The next morning he would meet his big sisters for the first time and I was nervous. How would my toddler react? Would she be angry? Would she be excited? Would she cry? My throat tightened as my family spilled into the small hospital room. I held my breath and studied her face as my husband led her in by her little hand.

The moment had finally come for them to be introduced and she eyed the blue bundle skeptically from the safe perch of daddy's shoulder. Placing her brother in the clear bassinet, I beckoned her to the hospital bed. She sat in my lap and we snuggled. The intimate act wordlessly assured us both that no one could ever take her place. After that, she was happy to coo over our new family member. She smiled as she examined his little hands and kissed him on the forehead.

Though the transition has had its moments of juggling and jealousy, she is adjusting well and loves being a big sister. She is helpful, gentle, caring and learning so much from having him around. Though I couldn't really picture it before, I wouldn't have it any other way. It turns out that I didn't replace my baby with a newborn at all. My lap, and my heart, have plenty of room for both to be my babies.