I recently had my sons newborn shoot done and the photographer has sent me all his images in kB, is this right as I have always received MB files from previous ones. Will the quality be ok when I go to print a large size picture?


I recently had my sons newborn shoot done and the photographer has sent me all his images in kB, is this right as I have always received MB files from previous ones. Will the quality be ok when I go to print a large size picture?


KB and MB are units to measure the amount of digital information. Without getting into technical details, what is important for you to know is that a megabyte (MB) has about 1,000 times more digital information than a kilobyte (KB).
If a photographer provided a 1KB image to you, you have reason to be worried. If they provided a 900KB file - that is not very concerning. Keep in mind that the units can be used to describe the same amounts, such as 0.9MB ≈ 900KB.
In general, if the images look fine on your screen I would assume your photographer knows what they are doing and shared with you images to fit the use case for which you purchased them. If you purchased images to print, the photographer should provide images suitable for printing. If you only purchased rights to digital images without the intent to print, that is a different case.
As some other answers have already pointed out the measure unit means nothing in itself, although it's obvious in this context that you meant something entirely different. While it's true that you can measure the size of a file both in KB and in MB, in this context you clearly mean "the pictures are less than one megabyte"
That said, as everyone wrote, the size of the picture itself is not a straight index of quality: most image formats perform some kind of compression, which means they use a plethora of mathematical algorithms to store a bigger quantity of information in a smaller file; this can happens by trading off the quality of the picture, and on the other hand it heavily depends on the information stored in the picture itself, so sometime you can happen to have a small file with an high quality image or a big file with a poor quality image.
Finally, all cleared, let's come to the core of the question: will you get decent enough prints from this picture?
Well, quality is way subjective, and on top of it it depends not only from the size of the print but from the distance you plan to look at them. So here it comes some starting point, to at least have a rough measurement; just remember nobody can measure your expectations :-)
The magic word in printing is "DPI", which stands for "dot per inches"; this is a measure of how many "points" we fit in a inches when printing.
Let's take a 2084x1528 pixels image and print it at 300 DPI. Math it's easy:
So at 300 DPI, for example, you can print your pictures at a size of 7x5 inches. Stay with me, we are nearly finished.
I used 300 DPI 'cause is a way common number when it comes to high quality printing, but that's not a magic number. What's the next step? Well, pick your quality!
As I wrote most of it comes from your own expectations, but you can always start with some "scientific evidence". Taken from one of the many website reporting this table, here is a list of common DPI numbers you can use a starting point for your decisions:
Finally, two additional advices:
Your intuition is right. Modern cameras produce higher resolution than pictures you posted. Also the photos have the photographer logo, so the image is a result of post-processing in a graphic editor. For example the child skin on forehead looks edited (fashion magazine like smooth).
Best is to ask the photographer also to send you the original camera files. They might not look as fancy, but they are like negatives, preserving all information from the photo.
If you like the visual edited result, then maybe ask the photographer to send the image saved in PNG-24 format (it contains more information than Jpeg). Or if the photographer agrees, the original graphic editor files (e.g. PSD or TIFF).