S.H.
This is a baby's natural development.... before actually "walking" they pull up to stand, lean against furniture and toddle around along using the furniture as a way to inch along and "walk." This is normal. This is "pre-walking." And yes, it does start to occur at about this age...both my kids did this as well at this age, although it is "early" skills that are emerging already.
Skills like this are instinctual, and yes, her legs will straighten when you want them to sit because their gross motor skills are changing... and this is the way babies/children learn. It's normal.
Before each "skill" is FULLY developed, a precursor to actually "mastering" it is this. The same will occur for any major developmental change.
When SHE is ready to actually "walk" without support or without help...then SHE will be ready. I would not expect her to "walk" marathons and for long distances, because yes, their skeletal structure and muscles are adapting and developing...but when SHE is ready, she will walk fully and independently.
It is not "better" or "worse" if a child walks early or not....nor does it show "intelligence." It is just an individual developmental occurrence.
For each phase of development, it serves a purpose. Just as crawling develops a baby's spacial and abstract comprehension and not just a "muscle coordination" skill. It is multi-faceted. So bear this in mind.
Sometimes, a parent is too eager, understandably, and tries to hasten the "development" of a child's motor skills... but unless she has a problem... there is no need to do anything "extra" to make it happen faster. 7.5 months old, to be expecting her to "walk" fully and independently is jumping the gun. Each developmental phase has it's own pacing, PER the child.
Good luck,
Susan
