
I suggest to read the main story which is the sequel of this story. There's no romance so far in it and manga updates' tags have no romance or even hinted romance in it so far.. It's much more enjoyable to read with unknown future than this one whose' future is already known (if you have read the main one already).

If it were me I'd prioritize nutrition (since she's very malnourished already based on her status).
Next is sanitary! (soap first before tub!!), then wash clothes first! (temporarily) since they have water, can take a warm bath and wear a cleaner currently worn clothes (rather than buy and immediately wear new clothes before taking a bath or creating soap!!).
Before buying clothes (better looking clothes are suspicious in slums, they can be robbed or harmed thinking they have good source of income or have hidden wealth) then after registering to the guild, look for new residence.
That's when you think of creating bath tub after changing residence. Living outdoors are not safe specially for a teenage girl & children! (although it's cheeper, they can't protect themselves yet and very susceptible to weather conditions).
For the bath or container, can't they hand craft/make it or find cheep alternative if they can't make one but can somehow be cleaned with soap before creating it using magic?
Indoor residence should be chosen before creating a portable bath for transport (if they're going to bring it with them everywhere).
I can already sense the irrationality of MC's train of thought in just 3 chapters.
╮( ̄▽ ̄)╭
Well, the following chapters were more entertaining and less cringy (logical-wise) so enjoy up to the latest chapter~
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The web novel version have more sense, they bought clothes but doesn't wear it immediately and clean themselves every night, wash their clothes every morning.
The web novel are up to chapters 110 (syosetu latest update was in last year, I'm not sure if the author updates it on other platform or have a light novel for the story updates)
The manga latest chapter is 11.2

This is the prequel story of The Reincarnated Great Saint Hides Herself as a Saint. The beginning story of Seraphina from Sirius' the white knight's perspective? (not sure who's perspective from).
If you have read the other work, you'll know this story's direction (ending).

[Major spoiler for this prequel story]
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The ending of the story from the prequel is tragedy, that's why the main story is the reincarnation story (after 300 years). Sirius was only shown through flashbacks so far.. His reincarnation is still unknown so far, since there's no one who have memories of their previous life except for the MC saintess (but my guess would be the captain of the 1st order).
There's a hint of mystery in the main story of what will happen if other knights from the past (white & blue) also have memories of previous life or reincarnated like the MC saintess and what will be the outcome of the MC's life since there's someone one who wants to revenge against her.

Original Source web novel (done):
https://ncode.syosetu.com/n8836gp/
Latest manga raw chapter 29.2
source:
https://comic-walker.com/detail/KC_002554_S?episodeType=first

Unfortunately the translations of page 32 were really butchered┗( T﹏T )┛
This part was really interesting since Hirschur really almost guessed the 6 LEADERS of Ehrenfest correctly but based on the translations here, the clues were really confusing. I suggest check the light novel or even the original web novel using machine translation to get the intended context message. As for the names, you can check the Ascendance of a Bookworm Wiki page for the correct English translation based on light novel.
On page 34 also on the bottom right "did no one played it at the ACADEMY?" not at the TEMPLE since no one comes to the temple (really hated place)
Thanks for the massive updates up to the latest chapters (╥﹏╥) I can't thank you enough!!
I have missed the manga very much (only browsing through raw chapter images every updates without understanding the story)