sindan no kekka wo kiite, haha ha sukosi ansinsimasita.

Here, の links two nouns.

• 診断 = diagnosis / medical examination / doctor’s assessment
• 結果 = result

So 診断の結果 means the result of the diagnosis or the results of the examination.

You can think of A の B as meaning things like:

• B of A
• A’s B
• B related to A

So this is a very standard noun-modifying use of の.

Because 結果 is the direct object of 聞いて.

The relevant chunk is:

• 診断の結果を聞いて
• hearing the result of the diagnosis

The verb 聞く often takes を for the thing being heard, asked, or listened to.

Examples:

• 音楽を聞く = listen to music
• 話を聞く = hear/listen to a story
• 結果を聞く = hear the result

So を is marking what was heard.

聞いて is the て-form of 聞く.

In this sentence, it connects two actions:

• 診断の結果を聞いて
• 母は少し安心しました

This usually means something like:

• after hearing the diagnosis results,
• and then mother felt a little relieved
• or having heard the results, mother felt somewhat relieved

So the て-form is showing a connection between the first event and the second one. Very often, it suggests sequence or cause here:

• first, she heard the results
• then, she felt relieved

In English, the most natural translation here is usually after hearing or when she heard.

The Japanese て-form itself does not always explicitly mean after, but in this kind of sentence it strongly suggests:

• one action happens
• then the next action follows

So here, 聞いて is best understood as:

• after hearing the diagnosis results
• or upon hearing the diagnosis results

It can also carry a slight cause-and-effect feeling: hearing the results led to her relief.

Yes, the most natural interpretation is that mother is the one who heard the results.

In Japanese, when a て-form clause comes before the main clause, the subject is often understood to be the same unless context suggests otherwise.

So:

• 診断の結果を聞いて、母は少し安心しました。

is normally understood as:

• After hearing the diagnosis results, mother felt a little relieved.

That means mother is the one who heard them.

If someone else had heard the results and then mother became relieved, Japanese would usually make that clearer.

Using は makes mother the topic of the sentence.

So the sentence is presenting mother as the person we are talking about:

• As for mother, after hearing the diagnosis results, she felt a little relieved.

If you used が, it would sound more like identifying or emphasizing mother as the subject, often in a more contrastive or newly introduced way.

In many ordinary narrative sentences like this, は is very natural because it smoothly sets up mother as the topic.

Japanese often leaves out things that are clear from context.

If the speaker is talking about their own mother, just saying 母 is very normal. Japanese frequently omits possessives like my, your, his, etc., when they are obvious.

So:

• 母 can mean my mother in context
• it does not need 私の unless there is a reason to emphasize or clarify

Also, when talking about one’s own family members in Japanese, the plain kinship term like 母 is very common.

少し means a little, a bit, or somewhat.

So:

• 少し安心しました = felt a little relieved / felt somewhat relieved

It softens the statement. It suggests that the mother was relieved, but not extremely or completely.

This is very natural Japanese. People often use 少し to avoid sounding too absolute.

Because 安心する is the normal expression for to feel relieved or to be relieved.

• 安心 is a noun meaning relief / peace of mind
• 安心する = to feel relieved

So:

• 安心しました = felt relieved

While 〜になる often means become ~, Japanese usually uses 安心する rather than 安心になる in standard expressions.

So this is the natural verb choice.

安心しました is past polite form of 安心する.

• dictionary form: 安心する
• polite present/future: 安心します
• polite past: 安心しました

It is in the past because the sentence is describing a completed event:

• she heard the results
• she felt relieved

So the whole situation is being narrated as something that already happened.

Not exactly. 診断 usually means a diagnosis, especially a medical one, or a professional judgment after examining someone.

So:

• 診断 = diagnosis
• 診断の結果 = the result of the diagnosis / the diagnosis results

Depending on context, English might translate this naturally as:

• the diagnosis
• the test results
• the examination results

But the Japanese word itself points more specifically to a diagnosis than to just any test.

Yes. Japanese word order is more flexible than English, as long as the particles make the roles clear.

For example, these are very similar:

• 診断の結果を聞いて、母は少し安心しました。
• 母は診断の結果を聞いて、少し安心しました。

Because particles like を and は show what each part is doing, the sentence can be rearranged somewhat without changing the basic meaning.

That said, the original order sounds natural and easy to follow.

The comma helps separate the first clause from the main clause:

• 診断の結果を聞いて、
• 母は少し安心しました。

It makes the sentence easier to read and shows a pause, much like in English:

• After hearing the diagnosis results, mother felt a little relieved.

Japanese commas are often stylistic, so some sentences can be written without them, but here the comma is very natural.